Used most all of the H lenses on the S2. I also have the S 35, 70, 120, 180 in CS versions.
The Hasselblad HC-50-II (35mm in 135 DSLR terms) is a focal length not available in the S lens line-up and is as good as the S lenses, The 100/2.2 is also unique and when used on the S camera is the fastest aperture AF lens available ... wide open it can display a bit of CA which disappears when stopped down. The 300/4.5 is also a unique focal length on the S camera.
All of the HC and HCD lenses have been DAC corrected by Leica, and they appear in the lens corrections drop down in LR.
The S35mm trounces the HC 35 which is an older film era optic. The HC 120/4 Macro focuses down to 1:1 where the S120/2.5 Macro has a faster max aperture, but can only focus to 1:2.
Focus speed for the 50-II, 100/2.2, 150N is identical as when used on the H4D camera when the AF is assigned to the rear thumb button on the S camera.
I sold my H4D/60 and am selling all of the HC/HCD lenses except the 100/2.2 to use on the HTS/1.5 mounted to the S2.
S2 Sync speed of H lenses is 1/750.
-Marc