Contrary to what everyone so far has said, I think the duelist has always been better than the warrior. The weapon abilities are strong and varied, and have only gotten stronger in recent patches. The abilities can get you out of so many jams, especially the shield one or the dirk one. And the abilities that daze your enemy (hammers, axe) or increase your attack speed and accuracy (scimitar) make combat so one-sided.
You don't need armor if you kill everything in a couple turns with a high level weapon and guaranteed hits. I have ascended so many times with just +4 scale armor.
I usually play Champion, but sometimes Monk if I get a good wand early. I've definitely abused the hell out of using Round Shield for invulnerability coupled with Meditate. You're immune to all attacks while meditating and then you heal and get wand recharging. I guess that got nerfed though, by not giving back as much energy now.