I managed to get two of the mages to 32 quite easily solo. But it still took a good 8-9 hours more for each. The mobs get a lot harder after 25, and there are less and less easily exploitable vulnerable mobs that have low melee attacks (after 25, they all have at least 2). But I do have one or two great areas I can use, and wands that will do either DEVESTATES or OBLITS on softened, vulnerable foes :) I shit you not, I four rounded a mob for 400 exp when I got an unspeak once. Unfortunately it's like, that one mob in the area and then I have to leave and rest. Otherwise that'd be sweet levelling.
In theory, the shapeshifter should start to improve drastically. The Conjurer I could EASILY get to 32, then it's a struggle to get to 35 for the archon as the area I'd use becomes much less exp. The shapeshifter should start to improve, I might even use it's water form (and once I hit the third tier form, easy street). The necromancer has wraithform, perfected parry and will get vampiric touch soon. Once I get touch, and maybe get a level above it so it's easier to cast, the necro will just fly up using it on vuln negative mobs. The transmuter will actually improve but as mobs start to get better defensively, it might not be worth using adrenal burst and I'll start to slow down. The AP will continue to be easy for a long while, especially once he's decked in some nice gear. The one problem I foresee is the invoker. That guy was a serious pain in the ass, and I think I'll give up at 25 :p I took affinities I thought would really help him in solo ranking, and I missed the mark a bit and lost out. Maybe if I can get to 30, I'll get lucky with some aura and shield wands I can abuse. But other than that - just no way. What the invoker really needs to solo, is a good way to heal, better redux or better defenses. Until I find a way to supply any of those, he's dead weight.
Yhorian