I've been playing Zone on Bovada (6-max style of Zoom basically). I've played both and various formats of 9 and 6 max on different sites. MinhAN is right, there's quite a bit more aggression and that's probably an understatement at 6 max let alone a Zoom style format. So there's people stealing blinds, stealing pots, and of course many only playing premium hands since they don't have to wait to get action. I've rarely seen an unraised pot pre in 6 max Zone poker, someone is always betting and in general since in Zone style you can wait for great hole cards, a lot of blinds and small pots get taken down easily.
That said I'm still working it out but find the variance is higher and the aggression can create lots of swings. Basically bet your made hands hard for value but if someone goes re-raising you like a maniac and you don't have the best hand, fold. You'll be surprised how many small pots you take easily with 3/4 pot sized bets on flop. Oh and raise on the button but be ready to fold. You will play for stacks on turns often as well Ive noticed so you HAVE to make bets when you get a decent hand to cut their pot odds
on drawing boards.