Leveling from 88 to 100 was pain in the ass. At those last 2 levels regular mobs would hit very hard and if you had more than 2 on you it was shitsville and no amount of feint and recouperate would sweeten the deal. I was actually unable to tackle some of the strong rares because they hit harder than me and I just had to vanish to escape with my life.
I thought it was a just a leveling thing, but now I'm 100 in full 620 gear (pvp) and the same shit happens. I'm actually avoiding level 100 rare mobs because odds are I may have to run with 10% of my hp. All these tools, they don't do squat, some rares can't be stunned and if you vanish he instantly resets. There was this rare ogron in Nagrand at the ogre arena-town thing and he fucking beat the shit out of me several times without even dropping below 50%. Then I logged my equally geared dk out of spite and killed him easily. All those tools that make people cry in pvp, are worthless against the stronger PVE mobs.
On my dk, warrior, monk or hunter I fucking breeze through whatever, even take 5 or 6 regular mobs and beat them up. Nope, not with a fucking rogue.