Upload & Sell: On
I've owned and used several 5D's for just this type of work. Yes, they're great, but now I'd really really miss liveview for this kind of thing, the viewfinder or angle finder just isn't as good. I rate the 18 meg crop sensor on a par with the original 5D for image quality at low ISO so if I were you I'd just buy a 10-22mm, I don't think you'll see any benefit in a 5D for interiors, plus the 7D LCD is miles better
I'd be really hard-pressed to say the same thing. I found the 7D had noticeable grain/noise at lower ISOs, similar in structure to the 5D Mark II noise at lower ISO. I also found its images weren't as natural and easy-going as the 5D images. Higher ISO images (800 and up) appeared to have some sort of built-in n/r, non-defeatable ... that gave the images a bit of a smeared look. That's how they looked to me anyway.
After shooting with the 7D (rented) and a 5D II (bought), I gladly returned to my 5D Classic (as well as my trusty 1DS II) for interior work. I'm a big-pixel fan ...