Wow, great read and really interesting AU. And very well done with the "what-is-real": at first I thought time-travel-story, then a short "maybe-in-this-AU-Atlantis-was-really-imagined"-doubt, but that was quickly dispelled because Rodney seems to know everything he learned about technology etc. in seven years and I don´t think he could have imagined this in a hallucination. So, time travel in a way. Reminds me of "Rewind, Restore, Reboot", only without a way back (and yay for interesting (plot) devices!) The details were wonderfully done (the cat, Jeannie, the mattress...) And Rodney with a plan for this reality is kind of scary.
I am now barely suppressing my urge to ask for "more, more, more!" and instead imagining how this world will look like in a few years... *mad grin*