How good is the original 5D Mark I compared to the 2013 Canon's?

The 5D1 does, indeed, still have a following. Its AWB is not as sophisticated as, for example, my 7D cameras. Its AF is not very impressive, away from the center AF point, compared to a 7D. The 5D1 OOC files, however, are very pleasing to my eyes. I use my 7D cameras at work, but like my 5D cameras for much of my personal shooting.

I bought my second 5D1 in December 2012, after considering the very attractive prices of still-new 5D2 cameras, but then deciding my earlier decision to skip the Mark II was still the better plan. My DSLR "road map" does indeed have a 5D3 on it, but I am not in a particular hurry to get there. When my finances improve in early June, I may prioritize acquiring another L lens, or two, rather than a new full-frame camera body.