Still playing my wizard, i'm in act4 now, and let me just say this, the archon form is awesome. If i enter an area and there's a huge pack of mobs, i can just use that and melt everything in seconds. And since every kill adds 1 second to the duration, if you go fast enough you can basically always be on archon mode. If something gets close to me, i can just use my aoe blast, or the aoe melee that deals tons of damage. With that, it only takes some lifesteal % or +hp on hit/kill to always be at full hp and melting through elites/bosses/crowds - everything. I'm not using it all the time because it kinda forces me to rush through levels and i want to take my time on the first playthrough, but once i'm done i'll definitely do some farming with it. I feel like it wouldnt be as good in multiplayer though, since i'd get less kills to sustain it.
Oh also, i noticed that you can make things a lot easier by simply buying stuff in the auction house. You can get really good gems for a very low cost, and all sorts of nice items to dramatically boost your stats. I died a few times now, but more often than not it was because of lag spikes (from having other users on my connection).