DS3 PC got slammed by many reviewers b/c the game itself is really nothing special; story isn't anything special; controls and gameplay are indeed different than DS1+2; and b/c the KB/mouse controls sucked out-the-box.
[Remember, reviewers normally review Version 1.0]
Even though they did fix the KB/mouse controls in a later patch [yay!!!!], I think the game STILL plays better w/ a X360 pad.
IMHO, DS3 is a decent game and easily worth $5, though there are much better games out there on the market...