For me, most of my problem with arcanum was just general implementation. Combat, moving around, general layouts of the place... not so much the balance, but basically all the stuff involving the actual gameplay and design. Even a lot of the dialogue trees and whatnot were just not really engaging to follow, for all that, yeah, a lot of the world building and such was pretty nice. It wasn't exactly
bad, especially when it came out, it just didn't feel all that good to
play, t'me. Have tried probably five or six times (every year or three since it was released, more or less) to get in and give it a go, and I usually give out before I get very far out of the second town/first city, if that.
... though I honestly have a similar problem with Planescape (except even worse, because I usually can't even manage to make it two quests out of the starting tower-thing before finding playing to be miserable and going off to do something else), so maybe I'm just fairly picky about stuff for that style of game
Any case, I wouldn't really warn people
off of it, just to not go in expecting too much, particularly on the non-aesthetic/writing parts (and to a fair degree, not those, either -- like said, probably one of the better implementations of steampunk on that front, but that's not saying too terribly much). Definitely only get it cheap (or
very cheap >_>), if you're going to.