Arcanum was buggy is awful ways (I had a character lost to an inexplicable object in my inventory that took up a lot of room and crashed the game when moved), but it was still amazing in terms of what it allowed you to do.
The magic build was overpowered (harm especially gregarious), but mind and conveyance made for a really interesting character without being instakill boring.
Similarly techonology could be really overpowered (explosives, tesla gun) but also really difficult since finding the components in the beginning was often a challenge in itself. Technology was way more interesting than magic, and the satisfaction of making your first zombie through technology (not a schematic available just from leveling up) was far greater.
Really anything could be overpowered: for my money nothing came close to the combination of stun (mind II) and backstab, or, if you are utterly lazy: throwing (ranged solid damage even with a powerless magical chakram, go tech for grenades, make molotovs, throw 15 fireballs a round)
My favorite thing about Arcanum was the love it gave to the criminally inclined. Being a thief was one of the best parts of the game, since quests for thieves were numerous, brief and interesting. I spent days running around Tarant, sleeping poorly, then richly, then only at the brothel, while planning elaborate heists around town.