I still remember that horrible amalgam of both, it had no powers of either one neither had it any personality, it was basically a slow, strong robot with k-nite in it's insides.
Beware the might of Ultra Metallo!!!!
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“I once had an entire race killed just to listen to the rattling of their dried bones as I waded through them.” —Volrath
Generally, not so good, if only because of Hank's technopathy, which, imho, surpasses Ultron's. In a head to head encounter, Ultron is more durable than Hank, but Hank has impressive repair/regeneration capabilities, and is otherwise superior physically across the board. Some versions of Ultron would give Hank a good fight aside from attempting to hack one another.
Sans technopathy, any version of Ultron since the female version would give Hank one hell of a fight (even the female version was a beast, tbh.) Where technopathy is concerned, Phalanx Ultron is the only version that'd rival Hank. Imo.
Anyway, Ultron wins easily.
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"I am tired of Earth. These people.
I am tired of being caught in the tangle of their lives."