Generally suspension designs with a concentric bb are subject to quite a bit of pedal bob. So they have good power transfer for the reason you listed, but poor pedaling efficiency. However I know nothing about the Hammerlink design so that might not be the case.
Truffles what do you mean? The pivot is around/on the bottom bracket (which also enables you to run SS) is a concentric bb like you said. With these kinds of bikes though I'd think they're so stiff anyways it really doesn't have 'bob' in the rear, not like XC or DH bikes which give you bump absorbtion. You don't need that with this kind of bike/riding style.
The the point in these shocks is to take the sting out of landings when needed. ive riden a cowan DS and didnt really notice the shock until overshooting a jump abit