I remember when Bats described Plastic Man as powerful, but to be honest, it just don't ring true.
I mean sure, Plas can survive an amazing about of damage. With no internal organs, physical force does limited damage. But he's still vulnerable to temperature extremes and sure as hell can't dish out alot of punishment.
Sure, in the right situation, Plas can be deadly. But that holds true of anyone. In terms of offense and aplication, he's very limited.