Overall, I found the Sword and Shield warrior easier. The 2-H one with Battle Rage III was awesome, but prone to dying in the Ark - two blows and a Whirlwind would finish most robots, but the crash after the rage wore off was dangerous! Over 80 HP would go while I was staying in the Fury zone.
I've now finished the game with a Staff Summoner Mage, Taliesin. This is the first time with this build and I left it for a while as the gods of RNG seemed to hate him. He threatened a extinction of dragons, but found no Magma Greatstaff. He racked up enough visits to the Ark that he had 100 Ancient Batteries, but no Tesla Rod!
That said, he did get three Rings of the Star Traveller, which is ridiculous! And he got a First Winter without hitch, as well as a Staff of the Traveller, so it wasn't all bad. Yesterday I came back to the build and finally got a Tesla Emitter when he braved the Ark Reactor (in one of the first rooms). Despite no training in Wands, he used this and watched with joy as EMP shock set in on the hated robots. He battled his way to the furthest ends of the Ark, and in the last chest in the secret room there, he finally got his Tesla Rod.
Finally properly kitted out the Sewer of Horrors was a breeze (unsurprisingly as he was Level 23 by the end of it). The Staff of the Dead Kings worked wonders on anything with a pulse in the sewer, and the Magma Greatstaff or the Staff of Impact did for the Undead.
The Staff of Impact was useful for the Insane Wizards and Ancient Guardians, and a Fire Elemental summons made the Elemental Plane of Fire straightforward.
His companion was Hirge, but he's now grinding solo:
STR 3 [6], END 4, AGI 2 [5], INT 9 [10], AWA 4 [6], PER 4 [6]
Staff Mastery IV, Mage Armour IV, Lesser Summoning II, Mana Surge II
Body Building II, Gate II, Mage Barrier II, Arcanist III, Fire Mastery II, Earth Mastery III, Summoner III
Solo grinding the Sunken Citadel is a cinch; he'll need to get some Scrolls of Wisdom from somewhere. They drop in odd places, as do the Greater ones.