If we were to scale the increases in durability/strength/overall capability to Hulk's level as to what Tony gets from the suit, Hulk would be haxxed as all hell. Even if the suit wouldn't increase his physical strength or durability any, just the extra options afforded to him would make him significantly more formidable. Assuming the Green Scar persona would be able to call upon Banner's tech know how and the like.
All those hypotheticals aside, he's not soloing the JLA. Lol.