Not too bad...
THE GOOD:
-Classic 2K gameplay. The 2K gameplay is outstanding and always has been. Its nuances demand you run plays and execute on offense and defense. Not adjusting is the fastest way to lose a ballgame.
-Player graphics are awesome. Most players look fabulous...and the cloth physics implemented make you just want to see players move around. hard to get enough of.
-If you have friends around, there are few games as enjoyable to play against someone than 2K6. Online makes it last even longer.
THE BAD.
-Some players have simply unrealistic flesh tones. I don't know who the art director was...and I don't know why the BLACK project manager didn't object, but some of the players (K. Garnett, J. Richardson) are black as MIDNIGHT...and clearly look poorly colored.
-Playing against the computer at times is unfair. You'll lose more than you'll win against the PC. And if you prefer to not run plays, you'll never win a game. If that means the computer has to shoot 70% to win...it'll do it.
-While some players look awesome, many others look NOTHING like their real-life counterpart. Even some of the real starts (eg. LeBron) don't really look like them. Others look down right scary. They must improve next time around.
-Coaches look like their lastGen counterparts. And they look even worse when standing next to their dolled-up players.
-The sweat is awesome.
All in all, 2K6 is an excellent game that's deep and blows away its competition. With some ammendments, 2K7 should be fantastic. But those things that were bad really need to be addressed, as they clearly and quickly take away from the gameplay experience.
If you don't have friends that would want to play 2K6 regularly with you or unless your favorite NBA team is really good, just make it a rental.