He had a lot of charisma on Dawson's Creek but hasn't picked great roles since. (Fringe included.) He needs to do lighter comic stuff. Not sure about The Affair but will tune in! My "I-don't-understand-how-he-keeps-getting-work" actor is Michael Trucco. Delightful in person, so blah on screen.
Trucco is probably easy to work with on set and looks nice on screen. In terms of acting, well, I mean as long as he can say the lines even remotely believably...