I have mixed emotions about this. I think it's great that Gill has resurrected the UB program, and it's awesome that the Bulls are going to a bowl game this year. I wouldn't mind if he stayed.
OTOH, he's the kind of coach needed at my alma mater, SU. Gill already knows how to recruit in this part of the country, which was Greg Robinson's biggest weakness.
IMO, Gill leaves UB only to take a job at a Big 12 school or in another strong conference, not the Big East.