Good question. I do think it depends on the comedian and the sitcom. There are some stand-up comics such as Carl Barron I would much prefer over some sitcoms such as The New Girl or Two and a half Men, but also some sitcoms I would prefer over some comics.
I agree with you about stand up, but not about comedies. The laughter reel is actually often genuine laughter by a studio audience watching the show being filmed. I find the laughter reel makes sitcoms funnier (laughter is infectious), and when there is no laughter, a sitcom can sometimes feel stilted.