This sounds pretty accurate to me.
Before Truth Superman could bench press the world's weight for days and barely sweat. Destroying everything wouldn't be a challenge, if extinction were his goal. He'd have the job done before anyone even realized what he was doing.
If he wants to take over, he has a harder time. The current DCU is much more cynical and less trusting, due mainly to the fact that superhumans are still a relatively new development and the heroic community hasn't had the time to utterly earn their trust (hey, the JSA struggled with that too). And Superman has had more than a few....unfortunate.....incidents in the public eye, including Doomed and his Year One war against Glennmorgan, which put him up against cops no one else knew were corrupt. Toss the damage Truth has done to his public profile in there, and Superman would have a harder time taking over. I think he'd still pull it off in the end, but it wouldnt be easy.
Actually, it might not even be that hard. This Superman is supposed to be Silver Age level smart (when DC remembers that) has doomsday level contingency plans in place; Phantom Zone projectors designed to move the entire earth and stuff like that. If he were so inclined, he might be able to just hit a switch and remove anyone who he thinks would be a threat to his rule. Of course, Im playing with several "if's" here.....