I appreciated the larger focus on character development this time around, the party of 6 gave a lot of space for experimentation, plus the instant unlocks from masks are nice even if RNG-y. In the end, I went with an ignis/guardian tank using hammers (for the stun passive), a blade/rogue striker dualwielding weapons with elemental damage buffs, a mechanist/sharpshooter (with shiftcloak passive obv) who was MVP for most of the game, a sage/scholar support character, an unmaker/{defiler/sorc/scholar} who was the MVP when the mechanist was slacking, and a late recruit enchanter/sage who felt kinda useless but at least this way I could have a full guard/regen/ward buff set on 5 dudes on turn 1. I also kept putting fire enchant on my blade, though I think it only works on the mainhand weapon.
Class balance feels better, though I didn't get a chance to try out many of the new classes (bat handler, warpblade, and I unlocked the spell archon just when I was about to finish the game). Berserkers look like they have some good potential. Unmakers in particular are really legit now despite losing their niche of undead-destroying. In full bone gear (mace+shield+armor) with some volskarn shards and no necromancer passive, my unmaker was the hardest-hitting character by far with various short-range instant spells, could refill his HP/MP each turn if needed, and the ruin aura would tick for like 16 free damage too. The mechanist could break many encounters in half with cheese, but felt balanced once actually in combat. The ignis knight was okay, I think mana is a problem, but the versatility is nice... funny considering the entire class is built around setting shit on fire. The blade was a decent performer, but kinda squishy with reliance on that 150% damage attack that also damages the user, and dependent on the enchanter to really wreck things. Bladestorm in particular was kinda blah, it looks like it doesn't use the offhand nor any elemental damage enchants, would've been legit otherwise. Defilers are strong... that "Power Word Kill" on <10 HP ability can get crazy, and killing a boss with the passive that makes it fire off whenever the user drops to critical HP is pretty cool (I saw that the constantly-spawning filler enemies in the last encounter had 9 hp, I don't think that was a coincidence
)
I played on the highest non-ruin difficulty (intense / ponderous), and it felt really brutal early on even after finishing VT on ruin -- and that's a good thing, imo! Particularly, the treedudes could literally two-shot anyone on my team since each of their attacks did 15 damage... had to be very careful how to engage them, and barely made it with no KOs. In general, I was really careful about avoiding KOs since I didn't want anyone to sit out dungeon runs... I didn't feel bad sacrificing my useless enchanter 5 times in the last battle, however. I noticed that the first KO from each character is a freebie (no stat loss), is that intended? The biggest change I noticed from VT, gameplay-wise, is that upgrades and consumables (not to mention money!) seem to be scarce. The only mithril gear I had for the end fight was the stuff I looted from the fixed NPC encounter just before it, f'rex... and I never had enough gold to even consider buying the stuff in Lorim's house. But then I think spending gold on party upgrades is a waaaay better investment (the +3 HP, +5 MP and +1 move ones are particularly no-brainers even after the party size is expanded to 6).
Encounters are definitely not created equal. The fixed enemy NPC parties (like the ignis knights, but also the group of 5 soldiers I encountered earlier on, plus the ??? dudes accompanying the eye guards) are probably the high-point, lots of tension without gamey bossfight mechanics. Speaking of which, that cave with the fire-spitting worms was nightmare material, especially since it only showed up in my first dungeon delve and never appeared after the party got strong enough to take revenge. Honorable mention to some of the newer monster types (the orb-legged speedsters as well as the camouflaged goop-spitting paralyzing jerks). That fight with the tentacles is still totally crazy (in a good way), as are - surprisingly - the smaller turtles who like to combine water spitting with a lightning melee attack, grrr. Shout-out to the gem bugs too, especially how they are encountered. I managed to catch one, I have no idea how you could get all 3 (ranged AOE stuns?). OTOH spiders are never scary, the shellworms were trivial even when I encountered them for the first time, and none of the worm types (pillbugs, the stationary turret worms, or the hexworms) really posed a challenge.
The most important part: cheese! I like that the prebuffing cheese no longer works, since buffs are stripped as soon as the combat starts. However, mechanist turrets and
especially their remote detonated explosives persist, which can allow a mechanist to blow up most of the encounter before it even begins. Throw a bunch of explosives in 2-tile range of the enemy frontline (sometimes even deeper than that), optionally set up some turrets facing the enemy, have an adjacent scholar recharge MP as needed, then initiate combat by setting off some explosions -- preferably max-range lightning from a sorc. Boom, most enemies are dead, and the rest are going to get hit for like 24 damage before they can get a turn. I'd recommend some restriction on this, perhaps making the placement of turrets and explosives hostile actions as long as their potential range is within the enemies' detection radius?
Completely random question: after killing the treedudes and withering the thing, is the only loot that 1 tile of buried treasure to the side of the zone entrance? I keep thinking I should've done something else with the seed too...
Brilliant design decision! 
