Heard today down at the bike shop after my first CA2 testride: "So JS... We thought that 21 hours at the HC600 was all you. We now suspect it was that preproduction CA2... Time for a rematch?"
 
That wasn't me that said that! I promise, John! :^)
 
CA2 vs Corsa - First ride thoughts.
 
I have some thoughts about my observations that I mostly will leave out for now. If you want me to comment further on something, please ask.
 
My shiny new CA2 frame arrived yesterday so I spent the afternoon and evening swapping the frame and fork out from under what used to be my Corsa. Except for cable housing, a different rear brake caliper and the larger OD steering riser, everything but the frame and fork was the same, so I figure this would provide a pretty good opportunity to compare the two bikes.
 
Equipment Differences:
 
The frame is subtly different so the carbon seat mounts at a slightly different (lower) angle.  I had to raise the seat stays a couple of notches to get things back to the measurements I had made on the Corsa.  Cable routing is slightly better, especially for the rear brake caliper. The rear brake mount for a 650C allows a more std road bike caliper and I used a fairly new Shimano 105 caliper that performed very, very well. The chain idler is mounted a little more outboard than on the Corsa which presents some slight challenges to my 11-32 rear cassette and long cage rear derailleur. I'm not done working on this issue though I did a few things to improve the situation. The BB cage is an eighth inch wider than the Corsa so my FSA MegaExo BB doesn't need a spacer. I had to redrill the carbon seat to match the new mount.  
 
The Ride :
 
A fairly gentle 50 mile ride with nothing more than about 6% grade hills and decent road surfaces.
 
To start out, the CA2 doesn't magically increase your speed (at least not until you get past about 30mph). The CA2 felt almost identical to the Corsa below about 25mph. I was expecting a smoother ride but really didn't feel that. Even though the seat position and angle is almost identical to the Corsa I think there is something subtly different that my body needs to get used to.  Below about 25mph I was slower than normal and felt a little puny. Once I kicked it up past 25, the CA started to behave differently though. Transitions from flat to climb were like silk as compared to the Corsa. No wall where you went from cranking to having to punch it to climb fast. I generally wasn't terribly impressed up to that point though. At least not until my legs warmed up a little and I punched the first climbing turn.  I tore into the turn, starting powering up at the apex and the bike simply took off. I was doing 33 up a 3% 1/2 mile grade and I wasn't even really up to power. Several more ~4% grades I tore up doing about *5mph* faster (over 30) than I have ever done them. Then on a long ~1-2% downhill against about a 10mph headwind I broke 40mph, followed by a flat stretch where I held 36mph for about a quarter mile against that headwind before I had to back down!  I could hardly believe I was flying that fast.
 
The rest of the ride was similar. At lower speeds and power outputs the bike was fairly mundane (like a Corsa :^). It was when I really powered up and especially at speed that the differences became evident.
 
Specific comparitive comments:
 
Especially on flat ground, cranking the Corsa hard caused a pretty severe head-shake. I know I induce it but it's there and I can't figure out how to really crank the thing really hard when it happens.  Absolutely nothing of the sort on the CA2. That 40mph happened when I was finally able to crank flat out and not have to power down to keep myself on the road.
 
Above 30mph the CA feels noticeably more aerodynamic. Not only can I crank harder to go faster but I don't have to crank as hard to go the same speeds as on the Corsa. With everything else the same, that pretty much leaves frame/fork differences to account for it.  The CA2 frame has smoother transitions than the Corsa. I think above 30mph they really start to pay off.  
 
Climbs are subtly easier. Hey, you still have to crank about as hard, but my broken feet didn't experience the same stress and pain on the CA2.  Now, several hours after the ride, there still isn't the level of pain I'm used to. For me, this may be the most important feature of my CA2 for long rides. I really have no idea as to why this is the case. Same chain, derailleurs, cranks, pedals and shoes...

The Corsa frame weighs 6 lb 6 oz. With fork 7 lb 12 oz
The CA2 frame weighs 4 lbs 5 oz. With carbon fork 5 lb 7 oz.
 
I can crank the CA2 a lot harder than the Corsa plus I'm pretty sure the CA2 frame itself is more aerodynamic and effects appear to show up above 30mph. I also suspect the frame is stiffer and more efficiently transfers power. Up my 18-20% road I couldn't discern any difference in climbing. Essentially the same speeds, same level of effort. I was really hoping the climbs would be easier but apparently not enough for me to discern. Since I was using the same equipment other than the frame and fork, I think the slight difference in bike weight wasn't enough to make a big difference. I couldn't tell much of any difference in ride quality. I suspect the carbon seat is the main factor that soaks up road things. Actually, individual pebbles seemed more noticeable but they didn't really adversely affect the ride. Maybe I was just paying more attention though.  
 
Note that the main differences occurred at high power output levels. At lower levels, I think what you said mostly applies.

I would maybe suggest that the benefits of moving to a CA2 vs a Corsa are greatly reduced if you can't hit 30mph on a Corsa on flat ground without a strong tailwind. Note that my Corsa had aero wheels and a carbon seat instead of the stock euromesh, which made a big difference for me, but it still took me months of fairly hard training before I could do it. Maybe a CA would help bump you over the line and start moving you up the power curve easier than a Corsa would.??? I don't know really know.
 

vs. a slightly earlier version of my Corsa

Maybe what I ought to say is that the differences due to the *frames* are fairly dramatic over 30mph, especially when you throw in aero wheels and not all that dramatic under 25. I would expect the stock CA2 bike should be noticeably better than the stock Corsa, but I didn't compare those two items.

I put over 12,000 miles and 60 centuries on my Corsa since March 2008 including riding to Florida and back averaging a century a day on that bike. Though I have ridden bikes most of my life I had only done rides of over 100 miles 3 times before I bought the Corsa. That bike opened up a whole new world to me. It has simply been an amazing vehicle. There has been expressed a concern whether the CA2 is worth moving to, and I think that concern says a lot about how good a bike the Corsa actually is.
 
The CA2 sure is a great step up though and pretty visually impressive too! After all the comments it got yesterday in the short time it was sitting in the work stand on the front porch of the bike shop while we were pfutzing with the chainline/idler issues, Hank is talking about making me park it out in the front yard for advertising...

It's much more expensive to buy a heavier bike and lighten up than to just buy it pre-lightened.  Cause then you're buying double the parts.
 
There, I've just given you a justification.  Now give me $50.  

Kent, I hear ya.  I enjoyed the 700 miles(that's about how long it took me to get comfortable with the bike) on the proto-type CA 2.0 while I had it, then someone took it away(Schlitter) for RAO, &  didn't even ride the event. Hopefully, it will make another appearance in my garage.
 
The bike just kicks a$%.

I feel for you! :^)  Don't want to look back, as good a bike as the Corsa was. JS was probably afraid of you becoming competition! :^)
 
You know... With everyone talking about bents not starting at the front of the HHH this year I was a little bummed about having to work through so much slow traffic before I could open it up, but then I realized that by starting the bents at the front, most of the riders probably never had a chance to see a fast bent that way. All of the riders in our local club were laughing about what happened to their pacelines when I motored past them. Double and triple takes and finger-pointing and then trying to jump on my tail. Someone started calling me The Paceline Buster :^) because I was disintegrating every paceline I passed, either just after I passed it or just as I was catching them. And I know Gary on his Corsa wasn't too far behind me so we were probably devastating them with a one-two punch. And at every rest stop I would crank it up a bit for a little dramatic pass at ~30mph which got people there really excited for some reason. They were jumping and cheering and clapping and I was wondering "What the...?" Were they doing that for everyone passing them or what? I know I'd get pretty tired of it after a few thousand bikes passed me...
 
But from the reports I heard, I suspect mixing it up with the road bikes this year really turned some heads... (figuratively also :^)
 
Oh! Maybe my CA2 just got named. "Paceline Buster"! Yeah! :^)