Its better than 0.77. Armies now matter, and that makes battles (and warfare) cooler.
Champion leveling is a lot slower, and splitting the exp only makes it exponentially slower to get a good Champion going I think. Maybe Champs below level 5 shouldn't count towards the number of Champions?
I think battles in general are generating a lot less XP than they used to. Sure I'll run into a huge monster that gives 100+ exp .. but in 0.77 that would have granted me 200 exp easy.
Not only do Champions split the EXP, but stuff is giving (i'd guess) 50% of the exp it used to. period. Its not just a problem of armies only giving us the exp of the best unit, its a problem of everything giving way too little exp.
Either that, or maybe the EXP requirements to get to level 4 need to be lowered. (first three level ups)
As is, its pretty hard to even get a single Champion enough exp to level ... even if you use him with no other champions and fight everything nearby.
If the 'weak mooks' are supposed to allow new levels, then have them give more experience points upon death. As is, its really only worth fighting Bone Ogrers, Trolls, Spiders and Cave Bears for experience. The weak stuff doesn't give enough exp. Killing an enemy SOVEREIGN doesn't give enough exp.
I'm sure you'll find an answer. 0.77 was a bit OP on the Champion front, while 0.85 is pretty barren. But I kinda like barren in a lot of ways. It makes the game more challenging, and makes economies (and their armies) far more relevant. I just wish it was a bit easier to skip past the first few levels 
I'm sure that the AI is better. I haven't played enough to get a real sense of the AI, but I am hearing good things. There are still a few issues though ... an AI sovereign just kind of sat in between my cities and his ... waiting for his army to catch up I guess? Well, I attacked and defeated that lone Sovereign (early game). I've played only 40+ turns, and I fought the same sovereign (who decided to walk into the fray by himself) a solid 3 times.
->Lord Markin of the Gildar if it matters. All of this is my limited experience playing against Normal AI Gilden.
->I won't make a final 0.85 judgement on the AI until I can get some quality time with Challenging this weekend.
I see AI armies sitting right outside the city, while there is only a skeleton crew actually inside the city walls.
Once I attacked a city, it only had a few militia in it ... and then there was a larger army of regular units (outside the city) that I killed ... and THEN there was a third army that was just 2 champions.
Maybe 1 of the champions should have stayed in the city with the regular units since my army was headed that way? (with a couple units going with the 2nd champion I suppose).
->again, all of this could be due to being on normal I suppose. I just clicked "play now" without changing the difficulty, so I'm not sure.
Gold ... it seems to be a bit lacking in the early game. I don't mind, but early game taxes are pretty useless. The only source of early income is questing, and possibly conquest.
Production ... I run out of things to build. At the VERY beginning, stuff seems like it will take forever, but its extremely temporary. Once you get a little bit of population going, and maybe a workshop and/or lumbermill ... you can quickly build anything you want (which is fine) ... but then all you have to build are units, and that early in the game there is no good reason to 'shut off production.' So you can unit spam, which is fine, but you won't make enough gold to pay for those units (other than quest gold and item-selling gold).
Spider Sac ... adds ZERO cost to unit cost. Basically all your built units can get Spider Sac for free. (I'm sure this is a bug)
Archers are automatically killed, or something, in auto-resolve. My 0 attack pioneer managed to kill an archer in auto-resolve ???