I don't watch Fringe, but I like FlashForward (for the most part).
I agree that it can be slow at times, and I censored one episode from my 13 year old daughter because of the lesbian content.
I wonder why these new shows, like FF and SGU, seem to find it really necessary to include that crap. SGU will never be a show that I can watch with my daughter, simply because of all the random sex between whomever for whatever reason. And because of the general crappiness of the show, I will not be watching it anymore anyway.
The best series' never need a strong (or in these cases, controversial and/or purely gratuitous) sexual content. They are good because of the storyline and the acting - not because they are showing people making out.
In the Sci-Fi genre - Bab5, Star Trek, The Prisoner (old, not new), Twilight Zone (old...), Firefly, X-Files... etc. They stood firm without resorting to PC games of making 'everyone' happy with the sexual preferences of every deviant group.
Personally, I find it sickening that I can not enjoy a prime-time show with my daughter without first recording and previewing it for inappropriate sexual content.