I agree that the younger male lead is rather lackluster. Even worse is the stereotypical tubby best pal doofus. I have never been a huge fan of George Segal, but I love Jessica Walter, so that has kept me DVR-ing it. She looks amazing for 70, proving that there are amazing plastic surgeons in LA after all.
I also enjoyed Christine Ebersole as the cougar-ish one-night-stand-who-turns-out-to-be-the-adoptive-mother-of-the-african-american-bartender-who-is-the-secret-lust-of-the-young-male-lead. Like Hot In Cleveland, it seems one goal of the show is to trot out oldster TV semi-celebs for guest star turns, which isn't exactly a bad idea.
I'm not sure where the show is headed, especially since the guy really didn't exactly "Retire @35". It seems he quit his high-power financial job? I think it would have been better had he somehow hit the big-time money-wise and actually "retired" rather than simply being the age-old storyline of prodigal son moving in with the parents.
More hit than miss so far, but barely.