The suit weakens him tremendously- that was the point. He couldn't control his powers at all- he kept ripping through doors and smashing computers and he thought he'd kill his relatives if he saw them.
Anyways, he seems pretty strong and durable- we haven't really seen that much out of him.
Colossus has a huge experience advantage in this match, too. I'd say he takes it- from the appearances we've seen so far from Citizen Steel. Maybe Citizen Steel is tossing around battleships or something in JSA 14, but I'd doubt it.
It would probably more than double his strength, but his durability may go down slightly. If that counts for anything. Hes already pretty durable with his organic metal skin. Hed also be faster, but like Mungi said, we dont know how good hed be.
That was really odd to me. Just how durable and strong is CS? I mean MaGog had just beaten KC superman who is stronger than regular superman, and like the whole JSA. Only to not be able to knock Steel down? Maybe that is his power. And the only reason I think he was able to throw Magog is because he caught him off gaurd.
Well it wasn't Gog. It said so in the story. In kingdom come, Gog had a for runner type or understudy or what ever. And his name was Magog. So I figured it was the same kind of thing.