IMO the OS engines are especially good for beginners... all of mine have started out of the box and have needed only a few clicks to tune properly... this makes up for the difference in price...

The LA series while a bit anemic in power (which you can always make up for by going to a bigger engine) are relatively simple to tune as well, but do not provide as accurate tuning... but they are cheaper.

I like the T.H. .46 engines and the .75 with a a couple of caveats... these are MUCH harder to tune and get broken in properly... I find that they really don't settle down until they have had a gallon or more of fuel run through them... getting them dialed in is tough, but once done they are reliable and powerful engines... now the .75 muffler mounting bolts are on the wrong side of the cylinder head IMO.... ugh what were they thinking! The T.H. and GMS engines are made by the same manufacturer.

I've seen club members curse the SuperTigre carbs, but I haven't had problems with them. The engines run well but develope slightly less power than the O.S. and T.H. equivalents.

The Evolutions are good engines BUT the limiter collars are a needless pain to deal with and they normally act to prevent you from properly dialing in the engine, even when the limiting pins are pulled out! More grief than necessary.... which lowers them in my list...

I've never tried the TT engines, but many club members really complain about them.