Yeah, he's way variable. In the New Krypton period for instance, his Jimmy Olsen stuff was cool, the Atlas (and Krypto) storyline solid. The Captain Atom backups ... pretty meh. But the Mon-El and Guardian stuff was pretty decent, and oddly more interesting than Rucka's Nightwing and Flamebird storyline running parallel. Rucka and Robinson were co-writers on "World of New Krypton", though, right? That was a solid book.
I thought his "Dick Grayson Batman"/Supergirl Justice League had cool concepts. Conversely I thought everything he touched related to Green Arrow was a total disaster.
I was having trouble thinking of the last DC thing he did that I read, but it popped into my head - the Not Quite New 52 "The Shade" maxi-series. That was a damn fine series.