I watched all of Atlantis but not all of SG:1.
They were both similar in target audience (pre teens or early teens) and similar in small individual stories, light hearted, and action packed.
SG: Universe went a very different direction: We got to know all the characters deeply, every episode was well written with no goofs or silly plot holes for the sake of advancing the episode.
It was probably darker, the threats felt more like threats and less like "this week's goofy minor hick-up" or McKay talking about how he only has 10 seconds to save the world and that he would like people to give him some space and quiet time, because it's SUPER important that he does this now... with now only 3 seconds left!
That's fine every other episode if you are 12 and just want the day to be saved and there's nothing wrong with that. LIght hearted and nothing to invest too much into.
But Universe was for grown ups and I don't recall a single thing I thought was stupid or illogical. Even the "conscience swap" with people from back on earth was done elegantly and intelligently.
The reason it was doomed from the start was all the angry Atlantis fans who never forgave the cancellation of Atlantis, which means an open boycot was determined even before the first Universe episode aired.
A shame, so well written, and that score! I've heard that many many times ever since, it was masterful music for each episode, kind of like Firefly.
I still watch all 40 episodes from time to time, you can too if you want a really good show with an open ending. :)
