I have no knowledge of the other people in the race, and I really haven't followed what he's been doing in as a state rep, but I met Bryan Lentz several times and he seemed to be a decent guy. I was impressed with his basic campaign strategy, which was to knock on every door in his district, a feat just about doable given the size.
Anyway, whoever wins the primary hopefully Dems keep Sestak's seat... well, hopefully a good Dem keeps the seat, anyway.