Being worth $400 is a decision only you can answer. The PS3 has other games you can get too, plus you can make the switch over to blu ray movies.
But there is a reason why it gets so much hype and attention. It's the best baseball video game ever. I played 2k9 at my friend's place the other weekend, and I was amazed at the lack of polish and total arcade feel of it (amazed how bad it was
). But to stay away from 2k9 bashing, yea, The Show is the better game.
Gameplay is pure, yet a little challenging. The first time I played 2k9, I was able to knock about 22 hits and 12 runs, lol. The first time I played The Show 09, I was shut down by Jake Peavey and scattered 5 hits or so, and loved it.
The AI is smart and punishing.
It has it's share of bugs, just like any game, but none are gamebreaking. Don't forget that those threads you are referring to are for people experiencing bugs..so obviously it will sound like the majority.
You can also head up to your local Gamestop and play the Show demo. Most of them have a PS3 setup with some demos.