I recently watched Battlestar Galactica, season 1. It wasn't bad, had some nice characters and ideas, but some elements (like that baltar dude) grew more and more annoying. Oh, and the Cylons stopped making sense at all.
Is it worth watching later seasons?
If you already are having issues, I would say avoid. The Cylons make even less sense as they go on (I think the writers admitted that from the end of the third season onwards, they just started making shit up - it shows) and Baltar's character is used as filler whenever they need to have a character be or do something later on. Problem with the show is that it's very easy to just watch episodes. I got to the end of the show and then kept finding more and more things wrong with it once I finished the ending.