I don't know is there any "rules" for that. Just play the game you like the most. 
Personally i don't like zooming because there isn't that much dynamics. One of my strenght (at least imo ♦) is adjusting my game and i can use it much better in normal tables.
In zoom i also hate that i have to make maybe too often maybe too tight folds just because i don't know ~nothing about villain. Even if you have some stats, it's possible that you haven't seen what kind of hands he plays, etc, etc.
It's also really annoying to try to find some hands in case you want to take notes or whatever. Sure there are Ctrl+Fold but i don't allways remember to use it, and that's when the fun begins.
When i was really thinking and constructing my pre-flop ranges i played mostly zoom because in every hand there was different kind of players in the table.
Just for practise i allways adjust my range depending what kind of villains i was against. I didn't care about sample sizes because that was just training.
Like you said, in normal tables you can choose what kind of players you want to play against. And when you've made up your mind, usually they also stay at the same table at least for a while. Speed of the game is also slower so you can use that extra time to thinking (even when you've folded) what kind of hands villains might have.
So my vote goes to the normal tables! 
Oh yeah, and zoom is rigged.. 
♠_evil:
