I'm playing a conjurer/shortsword/destruction-thingie at the moment. I haven't gotten double atronarchs yet, but the fact that my atronarchs have more powerful fireballs than me should say enough about how ridiculous conjuring can be. And I'm at like ~60 conjuring atm, dual atronarch should be ridiculous.
The thing is, though, that the three things I've picked up on that are considered hugely overpowered are supposedly conjuring, blacksmithing and sneak. Conjuring is definitely the harder one to level of the three, and no other kinds of magic are anywhere near it. Hence why a lot of people consider magic to be UP.