Been a full time pro most my life
When I switched to digital about 2001 I bought two canon 1D and a 1Ds since then pretty much all cameras stomp these in the ground

upgraded every model jump after the 5D MKII things did not change as much and jumped over to Nikon
Back to old days
My 1Ds forgot ? 11MP ? Crap ISO really lower dynamic range and color depth than basic cameras today etc.... Been in architectural digest numerous times with it was in Conde Nast Travel all the time both these sometimes with double spreads food & wine numerous times and many other high end mags etc.... If you had been to Maui before I moved away you saw my work most likely
Those are high end demanding mags ! Today my E-M1 would smear my 1Ds in every way
I did have a shot turned down with my 1D MKII was for a Maui calendar went reshot it with the S all was good
These days I use a Nikon D600 and OMD mostly
Am looking at sony A7 waiting for next gen most likely see where they go I do think mirrorless is the future and love shooting them over my FF DSLR gear
I gave up on 1 series bodies after the MKIII

I loved em but I never shot sports the 5D and the following 5d MKII and after were awesome wedding and commercial cameras
Today D600 or d800/810 no need to rent med format backs IMHO at least also the canon 5d is in the same boat
My fav camera is something most never heard of called a cambo wide

has wood handles
I never lug my Nikon out unless it's work related and even then I shoot my omd tend to get about 50/50 now
Agree kinda depends on what end use is but reality it's the one you like all are great and a great shot with say a sony rxIII or a d800 will be a great shot and if someone notices tech side rather than content it was not a good shot
If I won the lottery I would still shoot what I do now gear wise