Flavor is supposed to be great on both from what I've read on the forums and with my own experience with the Zenith V2.
I think the Quasar is a great looking atty, don't own one myself, but if you got the budget, buy both!
Personally I like the Zenith deck better, compared to what I see on the Quasar. The negative posts are machined as part of the deck (or welded?), I love the wide slits compared to the all too common drilled hole posts, and the allen screws make so much better connection than regular phillipps head screws because they almost never back out or strip at the top.
The delrin insulator located at the center of the top cap of the Zenith v2 is a Pro & a Con for me. It has been keeping my metal drip tips cool while chain
vaping, but I swear it's tightening up or something...
Overtime I've noticed drip tips that would fit perfect, now take more force to fit or feel tight. I can't completely explain why this happens.
Alternatively you could go with the
Veritas RDA which I've read new owners seem very happy with.