The game itself is indeed shorter, with less battles, but it's much more challenging and much more fun to play - at least in my opinion.
Since I got the game on my company's trip to Moscow, I was able to play it through a few times with all chars. I did give some info in other thread, but this seems like a proper one to pour some stuff out...
The game, in my eyes, is once again made for a warrior. The warriors get a neat last-tier skill that allows them to retain rage to a percentage of their total rage, meaning you will always have some rage even if you don't fight for a while. If you use up all your rage, you will gradually get back to the minimum amount set by this skill for free
Neat. The rest is pretty much like in KBTL - xp booster dragon skills, tactics, etc. In addition to that, the dragon is pretty powerful and with a proper dragon skill build-up you can use it on every turn, pretty much like a spell book - but of course, you get tons of rage per turn in combat, while you can't get that much mana per turn. It is very common to finish a battle with full rage and be ready for the next one straight away.
The mage is doing great, and the little tweaks to the Intellect attribute (like boosting spell power every point and such) make a nice change for the casting-oriented players. Now mass damaging spells like geyser and armageddon are well worth the buck, since with more intellect you can do some substantial damage (and not the fixed one in KBTL, where in time spells were easily outclassed by spirits' abilities in the endgame - in my opinion). Still, after each battle you will be pretty much hard pressed to wait a bit on the field to replenish your mana supply unless you managed to mana spring it back to full somehow, but not all battles allow for that - especially because there are armies without ranged or no-retaliation units. So... Emerald Green Dragons for the Mages once again, and heavy investment in the new Transmutation skill (up to 10 mana when an enemy units dies or up to 20 mana when an allied unit dies)
In my eyes, the Paladin once again gets the worst of the game. First of all, no resurrection scroll at start. It is replaced by peacefulness. Just great... Top that with the lack of good mana regen in combat - unless you try to get the best of all classes, which won't be easy, I promise you, especially because mana regen is a last-tier skill in the mage tree now. The paladin also gets the pretty much useless skill Resurrection which picks out a random stack of units that have died and resurrects some of them, in addition to boosting the similar spells of the Paladin itself and units that have it (Paladins, inquisitors and such).
However, there are a few good things about the paladin. Since he can go deeper in the mind tree, he can get a skill that adds 1 morale to Humans, Elves, Dwarves, Orcs, Lizards and Demons, as well as the last-tier Voice of the Dragon skill, which boosts the morale of animals and dragons by 2 at max lvl. So, one can try playing a paladin as a Dragon master. Top the high morale (+20% attk/def, +30% crit chance) with Prayer (adds some chance to all your units to get a crit - up to 10% at lvl 3) and Adrenaline (random unit gets up to +2 initiative/speed) and you can get a good idea as to where the battle may be going. However, as a Warrior, I could get a high-morale army without a problem as well.
As in KBTL, the Paladin performs better as a warrior than as a mage, using buffs and boosting spells to support his army.
However, just as in KBTL, the question remains - is morale and its bonuses worthwhile? That's one for everyone to answer for him/herself, but in my eyes, it's not. It's all too well and good to act first, but against an overwhelming enemy it may not prove to be enough in some cases. Sadly, the spells and the dragon are the backbone of pretty much any victory - and the paladin can't manage any of them properly, or to their fullest extent.
He still makes for a quite challenging and fun game with lots of tough battles though. And he (whoops, she) is still my personal favorite
That's my input for now... When I finish hard with both 3 chars I may add more. I'll try to keep it with less spoilers.