I have definitely had issues with it, but nothing any worse than people have with just the game in general, or with CC.
I had some crazy problem where these huge dark shadows would appear over ALL of my lots, and many of my lots were blue (this was NOT the normal blue-lot-syndrome that is caused by CC -- this was something crazy
If you don't update AM, you're really in for it in my opinion. If you don't want to update it, you can turn back your computer clock to an older date and bypass the "out-of-date" warning, but doing that messed up my game after a while.
One of my biggest gripes with it is that you pretty much HAVE to update it. If a new patch comes out that is really buggy and glitchy and you DON'T want to install the patch, you're shit-out-of-luck if you have AwesomeMod. Pescado updates AM with every new patch, so in order to play your game, you MUST install the very latest AM, even if it means installing a patch that you hate. I understand why he has to do that, but it's something to keep in mind.
AM can be really buggy for some people, and others seem to have few (if any) problems. But that happens with patches and custom content too. Supercomputer works better for some people (I have both). Also, the way you have AM configured makes a difference. You should ALWAYS do the custom configuration thing, and be careful of the ones marked "experimental".
All in all, I'm pretty happy with it.