Honestly, RDA was the heart of the show. Take out the heart and look what you got. The shows has felt like it's been meandering ever since he left. I've been with the show since episode 1 way back when it was on Showtime. Back then, Showtime just bungled the job and gave up and Sci-Fi should thank them for that. Nowadays though, they need to try something different. Bringing in the "Farscape" reunion crowd was definately not it. Farscape failed for a reason, and you can't blame it all on the execs at Sci-Fi. The show got stale and never appealed to a large enough crowd. I watched FS when it first aired and while I enjoyed it, it was never anywhere near the top of my list. That being said, the addition of Browder and Black (along with Bridges) has felt forced upon SG-1 and still feels that way. I can easily pick a top 50 episode list and none of the last two years worth of eps would come close to making it.
Sadly, Atlantis felt like the ugly red-headed step child when it first aired but has since started to look better. It will never be what SG-1 was with RDA, but it's good enough to continue on. Rumor has it there's a third series idea floating around that they hinted in the past would not see the light of day until SG-1 finished it's run. It will be interesting to see if and what they do indeed do from hre on out with the franchise.