As far as video pinball goes, this is not bad. But it falls short of the Pro Pinball games.
I played the Pro Pinball games on my PC, including Timeshock, Big Race USA, and Fantastic Voyage. Those tables are as true to a real pinball table as you can possibly get. And they set the standard for computer based pinball simulations.
Pinball FX looks the part, but when you start playing seriously, you are left wanting for more. The soundtrack for each table is generally pretty good, but does not change reactively to what you are doing. The sound effects are a mixed bag, mostly sounding like clips gleaned from some silly sound effects CD. And the gameplay is fast and difficult, not always a bad thing with pinball, but coupled with finding it difficult to know what to do with the ball, a real letdown.
But if you take Pinball FX for what it is, an inexpensive XBOX Live Arcade game, then you can still spend a few hours mindlessly having fun. And ultimately, having fun is what games are all about.