It's a little early to tell, but I quite like him. Bendis hinted several time at some events in his past to explain his demented hatred of all things Krypton. The fact that he seems to have a reputation terrible enough to force a surrender just by appearing on a battlefield, coupled with his ability to direct the Phantom Zone prisoners to attack Superman so easily truly makes him terrifying.
He may be a simple "Space Warrior", but his characterization is already better than Mongul (IMHO), who relies far too much on War World to be a tangible threat. Rogol seemes to be the Sins of Krypton coming to destroy them. Could he be the last of the Worldkillers from New 52 Supergirl (I seems to remember a missing one), or the result of another experimentation/earlier expansion in space from Krypton ? Bendis can still add a lot of information to him and make him great.