I never really liked Weir until she left and came back as a repli!Weir and I saw how well she played with the other characters. If the writers could have found something to do with her character other than wave good bye or screw up negotiations I think I would have been a fan of the character.
Carter was terrific in SG1 but really wasted in Atlantis, they wouldn't let her be the uber-genius geek that she is, so it kind of diminished her character for me. I liked Woolsey in the leader position, and wish they would have gone straight to that - leaving Weir as a Repilcator recurring character.
I didn't mind Keller, if she would have stayed in a supporting position as a junior physician. But as a major player and CMO she was awful. She was always the blonde in distress, an embodiment of the dream girl the writers (whose avatar was McKay) wanted to get it on with. And they played that angle with a passion that was disturbing.
Keller comes across as a young girl, McKay is a middle-aged balding man (who I actually like as a character). I agree with Rac that it comes across as a perverted, uncle hitting on his niece type of relationship. Friendship and snark between the two I could undderstand but I physically cringe when I see them together romantically. Uggggg
In Season 5 there are entire portions of the show I did not watch or can never watch again because of how disturbing I find the relationship.
All this said, I did like Season 4 a great deal, because the McKay/Sheppard Show is my favorite part of the series. The banter and friendship between the two was what held my interest and I did love Team episodes. My preference would be for a major focus on Team (Shep,McKay,Teyla,Ronon) adventures. (and more Zelenka and Lorne
)