Way to go, man! TAS is awesome. If you are a TOS fan, you will probably love the animated ones. Personally, I think the stories are actually better than TOS, and because of the 23-minute runtime, they don't drag on at all. The settings and aliens are always neat, with the writers being able to do things that wouldn't be possible in a real action series-- the episode "Bem" is hilarious.
The music is pretty nice, even if they replay it a lot. After watching a few, you might have the "generic action" music with the fast strings and brass stuck in your head.
Probably the weakest spot in the series is that Kirk never gets the girl, but I may be wrong, I've only seen half of them. And some people on Youtube were angry at Chekov being replaced by "E.T.'s Grandmother."