Guys, come on!!!
The 5D without mark is an excellent camera. Sure, newer cameras have more megapixels, but the 13MP do deliver excellent image quality. (Don't judge it on the display, though, 'cos this is horrible. Judge it on PC screen.) Dynamic Range is very good as well.
I regularly do prints in 50x70cm and they come out very nicely.
High ISO is still better than on any APS-C, for sure. No banding until ISO 1600, perhaps a bit at ISO H (=3200).
Prepare for a decent amount of sensor cleaning, however.
I'm confident the 5D it will become your first body and the 60D your spare second one. ;-)
I agree with all of this.
I have never owned or even used the 7D - so, maybe that would produce better images - and more often - not sure.
But I have used practically all the other Rebels and xxD Canons (including the 60D) and I very much still prefer the images from my old 5Dc (which I still use as a backup to the 5DIII).
The Sl-1, however, is growing on me as an alternate.
Stop reading and BUY IT BEFORE ITS GONE. Go out and shoot. Enjoy the FF!!
I tell aspiring photographers ALL THE TIME that a used 5D is a GREAT WAY to enjoy learning/enjoying FF photography for a steal. The 5D3 was the best thing to happen to the 5D used market. Now if you are a professional and need better performance, get the 6D for outstanding IQ, battery life and low light performance. But to get into FF cheaply, the 5D simple can't be beat!! And you'll learn to be a better photographer working within its limitations.
I've taken THOUSANDS of beautiful images with my 5Dc. I'll never get rid of it. Even now I would buy another 5D in great condition. Wonderful, beautiful, warm images. Yes, you need to work a bit harder on proper exposure but like above, I have lifted some amazing things out of poorly exposed images with Lightroom, etc. And the 5Dc will blow away every crop sensor out there, at least up to the 60D that I have. Before I got my 5D3, (I skipped the 5D2), I would ALWAYS use the 5D over the 60D unless I needed frame rate/reach for sports.
Think of the 5D as the "AE-1 Program" body of the DSLR world. Like the AE-1 Program of the film days, the 5D has an enormous loyal following of talented photographers that would pick one up anytime and love using it again.
Want more proof? Check this out... http://www.flickr.com/groups/5d/