Looks like there's good news for riders that like to run 23 mm, high-pressure, light-weight, high-performance tires on their recumbents. The Ultremo ZX is currently available in 650c and 700c sizes (I have a ZX on my Musashi's 700c rear wheel) and in the future will be available in 406, 451, and 559 sizes. Kind of pricey, though. See:
http://www.schwalbetires.com/bike_tires/racing_tires/ultremo_zx.
The total weight of my Musashi with me on it is about 172 pounds. I pressure the ZX to 120 psi and don't really experience that harsh a ride. I'm running a discontinued, 451 Schwalbe Stelvio tire pressured to 115 psi on the front.