Now we see through a glass, darkly...
- Apr 5, 2016
Once the 1D4 was removed from supported status, what other options did pro users have except the 1DX? The 5D2 wasn't in the same class in terms of ruggedness and performance.
I'd say the 1DX series succeeded despite its specs, not because of. Simply because there was no other in-system alternative.
The 5D Mark III, which improved in a lot of ways compared to the 5D Mark II as a camera usable by imaging professionals, especially in terms of AF and handling speed, released the same year as the 1D X: 2012.
The choice in 2012 was not between the 1D X or the 2008 vintage 5D Mark II, it was between the 2012 1D X and the 2012 5D Mark III. There were a lot of pro shooters (wedding, event, studio, etc.) who did transition from the 1Ds Mark III to the 5D Mark III instead of the 1D X.
I'm not sure what you think the problem was going from the 16 MP 1D Mark IV to the 18 MP 1D X was. The 1D X was an improvement over the APS-H 1D Mark IV in pretty much every metric that matters to sports/action/reportage shooters. It was faster, higher resolution, and Full Frame.
The 1Ds series had always been the slower, higher resolution FF model compared to the faster, APS-H 1D series.
It should be obvious to anyone who thinks about it critically that the 5D Mark III was in many ways the successor to the 1Ds Mark III at the same time the 1D X was the successor to the 1D Mark IV.