Mostly traditional. I will occasionally put down the $12.50 for zone poker (and I will play the occasional tournament). But I don't really like it for several reasons.
1. Since you can fold and pick a new hand instantly, almost everyone only plays very strong hands.
2. Given the insane fold rate, I will very often get a monster hand, but end up only winning the blinds because the entire table left.
3. I can't track the players. In traditional games, I can quickly learn who's vulnerable to steels, who's a calling station, who overplays, and so on.
4. Given the three reasons above, I feel zone becomes pretty much a crapshoot. And I am spending too much time and effort to learn the subtleties of the game to throw it away on zone poker.
Why do you prefer it?
It solves my single biggest issue with online poker... attention span. When playing a traditional game I find myself surfing the web, making dumb calls with **** hands because I want to do something, crap like that. I agree with all of your points though. Plus, zone poker is a bad beat machine. You can wait for premium hands all you want, but it always seems like when you play AK some other jackass played 10-3 suited and hits the flush. You hit the King with two spades, bet it strong...he calls. Third spade hits, he checks, you bet strong, he calls. Then he flips over the flush and you're like WTF? You didn't want to bet your flush? But he didn't need to, I bet it for him. Yeah, it gets frustrating. I just can't sit and play on a single table and pay attention.