Zen devs were incredibly bad about messing with my workflows that I had setup for Zen. So much so that I eventually just stopped updating the app and moved back to Firefox to let them get their goals together.

I use Zen for small things like research and whatnot, but Firefox will always be the only browser I use for serious stuff like banking and bills.

Zen is better these days, but the fact I can't get rid of the spaces crap really irks me. I don't need it, and don't want it, but it is a "core part" of their ethos so I am stuck with it. I just renamed it to ... and stopped worrying about it as much. Still recommend giving it a shot for smaller stuff, but definitely not banking and the like.