Even with the relatively low fire-res gear I have, a fire-mage is still cake, I just have too much hp to eat even if he crits so I'll always get a few moments up close and in any way: if I get any type of crit when I'm close, whether it's MS or a regular crit the Mage is pretty much dead.
Frost Mages might be trickier but a free action potion is never really needed (or used anyway, if my life depends on it I'd rather down a healing pot)
I'd say crits are needed against em though, and the top frop mage in my guild is just all the madness of the Gnomes in one.
His Frostbolts hit for 1300 and they've critted for as much as 2700 with arcane power in his high-damage gear.
His critgear... well, every single slot except the trinkets have +1 or +2 critchance to spells I believe
Thing is though... if a Mage jumps me while I'm soloing, I'm almost always dead.
If he jumps me with poly I still have a fairly good chance
If I jump a Mage myself he's dead. Especially since almost noone is quick enough to blink instantly after being charged out of a duel.
And when they do blink and are low on health = intercept + bloodrage and fuck em in the stun.
If poly'ed:
Switch to zerk + zerk rage after poly and get some rage
Get close: rape with a hit and MS + hamstring
He'll nova and I'll use the pvp trinket, if not equipped: I'll use inti-shout to freeze him up, then bandage myself...
break out, hit him... he'll eventually blink = fuck him up with execute if he wasn't dead already.
Problem always is: if he's good I won't get close
In any way 5200 health is a lot to eat up even for a Mage at times
Seeing as Enrage is almost always on vs Mages though, a MS will hit for either 700-800 ish, or crit for 1500-1900-ish, which is a lot of health