I dislike 30 Rock more than a little. Word play jokes don't go over my head, they just kinda bore me if they start getting in the way of the pacing. By contrast, I liked Mean Girls, but I felt like the jokes had more time to breathe in a movie format. 30 Rock's sheer density often takes the pleasure out of it for me.
Anyway, yeah, Shit My Dad Says is terrible and I don't understand how anyone can enjoy Shatner in that role. The Denny Crane role worked out OK for him because it was a side role and while the character was certainly ridiculous, a lot of that ridiculousness was a put on even the in context of the show. What little SMDS stuff I've read before, however, only hits me funny if the guy saying that stuff had more sincerity than bluster. It's kinda funny to think there's a guy out there who just genuinely thinks and raises his kids that way, particularly since the SMDS tweets read like if some pessimistic but decent advice was filtered through Lyle from Achewood. From what I've seen on the show, however, Shatner comes across more like he's openly fucking with his son's head, which is considerably less funny and a lot more douchey.