A very solid hitting/pitching interface is dragged down by poor fielding, baserunning and a bunch of bugs.
Graphics: The game looks great, I'm running it fully maxed out at 1920x1200 and things generally look amazing. The crowd in the lower deck of most parks are fully animated 3D models and they add a lot to the feel of the games. The crowd in the "cheap seats" are just flat 2d cutouts... and when you get a mix of the 3D crowd and 2D crowd in the same shot, it looks a little goofy... but a minor complaint. The player models all look detailed and are accurate down to batting stances and pitching deliveries.
Sound: The commentary team of Gary Thorne and Steve Phillips are pretty good. Steve with the color commentary can get a little repetitive. At least 2-3 times per game when visiting Toronto, he'll mention how some players don't like going through customs at the border. Gary Thorne is an old pro at this stuff now, having been the voice of EA's NHL franchise for years. The ambient crowd noise and crack of the ball off the bat is also very well done.
Presentation: The menus and interface looks great, but it's not the most functional and can be a little buggy. No hardcore PC user will mistake this interface for anything other than a port from a console. I'll give the 2K team some credit, as they did add keyboard shortcuts and some mouse functionality to the interface. While this keyboard/mouse functionality seems hit and miss in it's implentation, you aren't always stuck using only the controller to navigate. Still, the interface is big and clumsy and designed to be used from 6 or 10 feet away while you sit on your couch... like you would when using an xbox 360. There are also some downright puzzling omissions. For example, there is no easy way to see the opponents batting order when you are trying to get yout bullpen warmed up. The interface is functional, but that's about all you can say about it.
Gameplay (the good): The pitching / batting interface is very solid. Everything works via the analog sticks and for the most part, it's a rewarding experience. Delivering the perfect pitch or swing is hardly impossible, but it's not a walk in the park either. That said, the 2K team has made some big strides over the similar system used in MLB 2K8. In that game, you didn't get much wiggle room. Slightly imperfect pitches were hammered mercilessly. In 2K9, the game gives you some leeway to get away with "good" pitches that might not be perfect. Playing a dynasty on default difficulty levels, the scores tend to be realistic baseball scores. The CPU also does a good job at picking up tendencies. If you get too happy with that low changeup for a strikeout pitch, the CPU will stop offering. If you always try to get a groundout with a low and outside fastball, the CPU will start taking that pitch the other way for a line drive single. My only complaint with the pitching / batting aspect is the default camera view for batting. It's too zoomed in and low, which makes picking up pitch movement frustrating. By the time I would realize that a curveball wasn't actually a high fastball, it was already too late to swing. I fixed this by zooming the batting camera out and raising the elevation. This gives you a better view of the pitch movement without making things much easier and actually gives you a decent chance to lay off bad pitches and draw some walks. Overall, the pitching / hitting interface is the highlight of the game. It's challenging without being frustrating and makes for a well-balanced experience.
Gameplay (the bad): The fielding is passable at best, annoyingly awful at worse. The outfield being the biggest trouble spot, as there is no such thing as a routine fly ball. The game seems to want to turn every catch into a "running catch". So, the outfielders don't run full speed to a spot and camp under it (like it was done in every other baseball game since the NES days of 20 years ago)... But instead, they run/jog at various speeds, taking their sweet time so just about every catch can be on the run. This leads to uneccesary animations getting played for both the catch and throw back into the cutoff, which gives the baserunners that much of an easier time advancing. Also, the ball will occasionally just drop in front of them when the catch should have been made if it wasnt for the OF slowing down to a jog halfway through the play. Still other times, the outfielders don't even make catches that land right on top of them. Something gets glitchey, the "catch the ball" animation doesn't fire off and the ball just lands next to them and rolls away. In general, the outfield is the biggest annoyance of the game and needs some serious attention.
Bugs: Oh the bugs... I've played probably about 15-20 games, split between single games and franchise mode. The game has crashed four times (and remember, I am using the fully patched v1.1). I run Vista Ultimate 64-bit, so the 64-bit OS might have something to do with it. Two of the crashes have kicked me to the desktop and the other two have been hard reboots.
Also, the gameplay itself still has some bugs. Do you have two runners on with less than two outs and need to score? Send them both home after a routine single. The catcher will tag the first one out, but let the second one score! (Not sure if this works EVERY time, but I've done it on at least three occasions just to test... and everytime the catcher lets the second runner score and he's standing right at the plate with the ball). There also seems to be a baserunning bug with attempting to steal... If you are holding down the steal button but the pitcher checks you with a throw to first... you are going to be out... even if you slide back to the bag successfully. The word "SAFE" will appear at the top of the interface, but the announcers will start talking about how you were caught stealing... your player will start his walk of shame to the dugout and you'll have another out recorded. I am playing a franchise with a relatively slow team (Detroit Tigers), so I don't steal much... but this is still pretty weak. Then there are some random bugs with various walls in the ballparks, if a bad throw rolls to certain walls it just disappears and the fielders can't retrieve it... allowing the runners to advance all the way home. Also, sometimes infielders will charge ground balls and make the play, waiting for you to hit the throw button... but sometimes they will just stop their charge requiring the player to take over and guide them the rest of the way. It's very random.
Conclusion: While it might seem like the bad outweighs the good, I still really enjoy MLB 2K9. The price is right at under twenty bucks and the bugs usually don't appear enough to ruin a game. When that happens, I just quit the game and play it again so I can get a "bug-free" result. While I think this one needs another patch or two, I would still recommend it. The very solid batter / pitcher interface is worth the price of admission. While the fielding aspect is flawed, it's usually not enough to ruin the overall experience.