The FX is a far superior engine in many and more subtle ways than what has already been mentioned.

For one it is a very desirable engine and tends to retain its value for resale and retains your desire to want to use it in another airplane down the line. While the LA's any of them tend to get pitched in a drawer down the line. There are plenty of other brand "DRAWER" engines also and they do as advertised but they are just among the first into the drawer

The FX has far more aggressive port timing and venturi throat sizes which of course produces much more power but also in concert with the superb OS double needle carbs contributes to one of those more intangibles: Throttling or throttle response and this is a major but subtle factor with any engine.

If you can afford the more expensive engine then the answer to whether or not should you get it is a no brainer: You bet your Bippy

John