I just checked out 1.5 tonight after a few days away from 1.4 (which I played quite a bit) and here were some things I noticed..
I'm playing a level 14 Adept that was almost all cons so my HP for an adept is above average. Of course because of the item wipe I had no gear so I headed northeast to get some loot from the harder mobs..
The "novice" mobs would attack for about 1/5th my health each hit/spell/arrow, very challenging when you have more than 3 mobs on screen. I figured with that level of difficulty I should be good clearing these mobs for some better loot and make a level.
After clearing the entire area out a few times I was making decent experience but the drop rate was horrible.. I think a carapace, buckler, and some wristbands were the best drops I got after maybe 30 mins hunting.. so that's like 30-40 defense, either way it was not enough to lighten up the damage I was taking.
So I headed further east hoping to tactfully take on some of the harder mobs and DAMN was that a tough task... With quick transing, healing, and aoeing I could handle a single creep at a time, with the exception of archers. The archers hit for half my health, pretty much just like the other creeps but unlike the others, an archer would hit me twice in less than a second, meaning I was dead on sight with almost every encounter.
Since I was in desperate need of gear I kept at it and managed to get a good amount of kills in on these guys but again the drops sucked! My best find was an enchanted wrist band..
I'm not aware how hard these mobs are on a character with more defense but regardless it was aggravating not being able to gear myself up =(