Opinions are rampant on this discussion.

To generalise them: The OS LA series are not worth it given that for very little extra you can get much better alternatives. The OS AX is good, but is it worth as much as they ask?

So, OS "Brackets" the range with the LA at the bottom, and the AX at the top of the price range, and possibly the quality scale. Since you asked such a general question though, I'll provide my opinion (and I have owned buth the .46 LA, and FX which was the predcessor to the AX). The AX is not worth the expense, and the LA is just too "plasticky". Go fot r an alternate brand, and my brand of choice is the Thunder Tiger .46 PRO. Way better than the LA, about as good as the AX, but not much more than the LA in price.

I have no personal experience with the other engines you listed.

gus