Mine are Shimano sandals. They've changed since I bought mine. Mine have two straps; the new ones have three, so I can't testify how the new ones are, but I really like mine.
The soles are as stiffer than many mtb shoes, but not as stiff as good road shoes. I had trouble with hot spots on my feet back when I used spd pedals. After I changed to Bebop pedals, that wasn't a problem.
For socks, I wear Pearl Izumi Attack socks. When it's cold, I add wool socks on top of those, and
Rocky Gore-tex socks (it looks like they've changed some, too) over the other socks. I tried neoprene booties over the sandals, but didn't like them. I've found that if it's really cold, I can add those small chemical handwarmer packs on the top of my toes, and my feet will stay toasty.