DC is just one method of doing physics or animations. Its relatively new.
Compare CPU based physics in games vs physx. Not just havok either, but custom built into developer's game engines. If Physx is awesome, it would be everywhere since devs would use it without NV giving them incentives.
It's like green energy, solar/wind, if it was awesome, everyone would use it without needing tax rebates or subsidies.
Keys, Physx does affect me as a gamer. I enjoy some NV sponsored games which could have had better physics implementation that runs on all hardware efficiently, but no, i have to play the game missing out on its full visual potential. It's not a huge deal as most Physx stuff are gimmick effects, but its the fact i paid the same for that game and not allowed to enjoy all of it because i have AMD hardware. I'm just glad BF3 has its own cpu physics engine.