He was the best writer Teen Titans had in years, especially when Geoff Jones departed, and was the perfect voice for the modern group, which I beleive is the best ensemble of consistent characters since the Wolfman era. Ravager is exactly why I love the concept and I'm glad she's getting the focus she deserves. At least Sean isnt departing entirely, I think eventually he'll write at least one story if his Ravager back-up crosses back to the main Titans arc.
He's also the transistional writer on Titans until Judd Winik can be replaced (he's now writing Batman), I don't like where he's going with it (Judd did a great job fixing what OYL took from Jone's run), but I hope everything is back where it is before he leaves.