Just bought a second-hand (but one owner) 1DsMk3 and after arrival I tried is with a bunch of my lenses and pixel-peeped to see how it differed from my 5Dmk3. Liked the image at low ISO, which is exactly why I bought it. Oh, and for its great build quality and the long-life shutter.
I have had no other 1-series camera and the shutter on this body sounds sweet to my ears: more mechanical, more authoritative.
But yesterday on a real estate shoot with my 17mm TSE, tethered, I started getting these Error 30 messages on the screen. I believe it told me turn off and on again, too. The body never stopped working, and responded to the power cycle. Shooting tethered I was bringing up the images in Windows Explorer and right clicking to ask them open in ACR... just to check focus and the histogram. But I don't know how tethered operation might have caused -- or highlighted -- whatever is the root cause of the error.
Canon tells me this error is a loose bag of possible shutter issues. I was using an Odin trigger in the shoe but the VA-center tech person said that wasn't likely to be the cause. Ditto tethering, although he asked if I had been in and out of LiveView, which of course I had! I am so bummed. I know these things happen but I *thought* I had purchased this at a reasonable cost and from an enthusiast, not a pro, which meant lower actuation count. No signs of hard use on the body. I believe my cost just went up by $400 (a guess, I admit)
Important shoot on the 16th and despite my CPS fast turn inside the repair operation at Irvine I would have to spend about $100 to go with the fastest shipping service available, and here in rural Hawaii, often, "next day" is not next day either going or coming.
So, given that I MUST have a second body at this important shoot (and that it will be tethered photography of regular folks -- with people and groups stepping in one after the other, I am tempted to wait to send it, explore the body's reaction to all my TSE lenses, try tethered again, to see if there is any recurrence... and still, I guess send it in and pay for whatever repair is necessary at that point. Grrr.