I have to admit, I was resigned to hating this show before it aired. I hate Seth McFarlane (spelling?), and by association any of his new shows. I actually like the older episodes of Family Guy, back when there was some character consistency.
So no, I haven't wasted my time on the Cleaveland show. I saw the ending to one episode, and it was apparently about Cleaveland's wife's mother actually being a man...or something like that. I decided I was not going to subject myself to that kind of crap.
Though I might be being unfair. I actually did like the earlier episodes of American Dad. I did stop watching the show, not because of it's poor quality but rather because I don't spend much time watching TV now. When I did stop watching it was still far more humorous than Family Guy.
Though judging from most of the responses here the Cleaveland show is mediocre quality at best.