ORIGINAL: wcmorrison
All the foregoing is good stuff for you. None of the OS LA engines have ball bearings, they have sleeve bearings. The more expensive OS engines the OS 46AX or FX are ball bearing engines. As Ed Creggor said, go for a Thunder Tiger Pro which has ball bearings, cost less than the OS AX or FX and provides near same performance if not better performance. Do not rule out the Magnum engines either, they are also comparablae to OS AX and FX and also cost less too. You can also look at the Tower Hobbies 46 or the GMS 47, also comparable to OS AX and FX performance levels and cost less that the OS engines.
Frankly, there are a lot of good engines out there that cost less than an OS. There is no true mystic about OS except that they cost more.
I'll add that you may have to play with the alternatives a bit more to tune them up properly though... a skill worth learning...
Bench testing is a wonderful and informative thing...
The GMS .47 and the TH .46's have been GREAT for me, after they have had about 1-2 gallons run through them, whereas the LA practically ran fine on it's second tank.