There is a monk-rogue in my regular game that has the Catch Off-Guard feat. He carries around part of a chair and a beer mug as his primary, yet "improvised" weapons. By rogue level 3, he's doing more damage than the standard fighter, as well as hitting more consistently at the lower flat-footed DCs.
Is this correct? If so, it's a great build, with the standard rogue dagger replaced with the suddenly significantly better and cheaper fist-sized rock. If not, why?