My hardcore WD is 50 now. It's a bit slow going sticking to Hard difficulty, but better safe than sorry, and he at least has plenty of bounty mats and his cube already.

I dislike Firebird-archon immensely myself. For one thing, you have to get up close (because you need all 3-4 archon damage moves to be able to ignite enemies, including the melee range ones) which keeps you in harm's way. You're also forced to use ice armor on a fire build to survive, which irritates my inner Vorthos to no end. Third, you lose your ability to teleport, with all the loss of mobility and survivability that comes with that. I don't care how effective it is, I have no desire to push 90+ anyway, and even if I did, I'd be playing another build with some actual variety in it.

Contrast with the Lightning Vyrasha build, which is not only much more fun, it has greater survivability, and even managed to beat Firechon on the leaderboards. If I were interested in pushing as a wizard, it would definitely be with that.