Spellslinger was probably the fastest run, next to priestess. Buy damaging spells and increase their damage. One or two-shot everything and win.
Priestess ended up playing almost exactly like spellslinger, with mass spells that killed enemies before they were really ever able to use their barrier trait. It came in useful more to extend fights for a turn or two at the last survivable floor, a little defence to compensate for less raw power in the start.
Grave Robber was entertaining and the only class that could reliably pick up two abilities on the first run. It played a little slow after their regen picks up and starts carrying them, but faster and more fun than plague doctor.
Plague doctor was a slog that started being able to take most fights early but took significantly longer to do them. Was probably able to defeat the boss a few runs in but retreated just to make it go faster, lol. I liked the gimmick though, and it could have just been the luck of my rolls and build.
Knight ends up being either pretty generic or camping for the bulwark ability, there being little else that reliably gives a decent amount of armour. Hard to build for but not entirely nonviable, granted they have good armour from the start.
Samurai ended up being more entertaining than I thought, and quickly became both quick and immortal with 100% dodge and max speed. Yeah, exult makes them broken until they stumble into damage reflection or other evasion bypasses (which ironically required me invest into health, lol).
Assassin likes to end fights fast, but ended up being the only class where I lost (and more than once) to the final boss, with their initial evasion almost completely invalidating their class ability. I managed to proc a good lifesteal at a sliver of 1 hp eventually and that brought me enough health finally to finish them off. Neat trick if you can get lucky and roll damage-buffing abilities though.
And yeah, to be fair, exult is the one ability that can be used on pretty much any class and still synergize very well. But true, for its versatility it is a little strong once you get high int and duration.
The wraith earns the title of my most hated enemy.