Same basic feel. A lot more power is given back to the PCs - races have better synergy, classes get tweaked abilities, skills are more focused (spot and listen become "perception').
It plays just like 3.5. The biggest difference is that grapple, trip, etc. have all been boiled down into one system. You have a combat man. defense and a combat man. bonus, so it just becomes a single roll to see if you fail/succeed. None of the "Ok, i attack then grapple if it's raining on tuesday now I get to get hit back by you, but we're both grappled so that's at -4..."
All 3.5 stuff is fully compatible with it too.
C'mon...City of the Spider Queen is calling your name...