My partner got it for me a week or two ago because it was on sale for $3 and it's been a lot of fun so far. Reading about it kind of put me off from it because I thought the class/skill progression would be more similar to Path of Exile, but it's not. Basically at level 1 and level 10 you get to pick a class, but each class has its own set skill tree. For some reason the description I'd initially read made me think there'd be more granular customization of skills instead, which I wouldn't really like (because if I'm just mixing/matching whatever I want, it's hard for me to feel like my character is whatever class they're supposed to be? idk)
I would say it's actually A LOT more fun than path of exile and that the only thing POE does better is allow WASD + Mouse movement but maybe that's just a testament to how much I really, really hate POE's class/skill progression (OH BOY, I LEVELED UP. TIME TO PUT MY >>>ONE<<< SKILL POINT INTO: 0.2% HEALTH REGEN PER SECOND!! WOW)
I wouldn't say it's necessarily worth buying at full price but it's 10000% worth it if you like Diablo esque ARPGs and it goes on $3 sale again
there's apparently a mod I haven't tried that turns Grim Dawn into Diablo 2 but you can still cross-class so you can be a Necromancer/Paladin etc