Just finished up Arcanum for the first time in years (GOG version rather than my old box edition, plus the UAP). Nice to play this classic again. I absolutely love the setting, and really wish this idea would be used more often. "Industrial Revolution in a world of Magick" - it's awesome! The main story is great - paced well with enough twists to keep it interesting. The side quests are pretty hit and miss though. Some are are your average quests you'd find in any RPG, some really good little side scenarios, while some hint at greatness but end prematurely or in some unsatisfying way.
As good as the world-building is, the characters are pretty weak. Some of the more important NPCs have a lot of interesting history to them, but none of the recruitable party members reach that level. There's maybe 2-3 that have anything at all, the rest are little more than an introduction. Definitely a missed opportunity here.
Difficulty in this game is quite backwards. The first levels are the hardest and slowly gets easier, then you hit a build-specific power spike after which everything is a cake-walk. For this character, a Technologist melee character, the stars aligned around level 30 when I got the materials and schematics to build Pyrotechnic Axes, Machined Plate, Flow Disruptors, and other nice gear for my party. I also did the mastery quests for Melee and Dodge shortly after that which just added to the power.
Still, Arcanum is an RPG well worth playing for anyone who hasn't yet. I'm planning on playing through again concentrating on the Mechanical discipline. I want to have an army of robots kill everything for me. Still trying to work out a build I'm happy with before I start though. Also considering editing the NPC leveling schemes to make my followers spec a bit more intelligently.
Anyways, yeah. Arcanum. Play it.