I posted here in August about an error message on my Pro-4000. I won't go into too much detail. Long story short, the error message called for a replacement of the main board. I called Canon tech support. Tech support was disinterested to say the least. Tech support referred me to an authorized repair shop. Contacted the shop and while awaiting the arrival of the new main board, printer gave an error message that also called for replacement of the PSU. The authorized repair shop at this point advised against making the repair, and to replace the machine.
I ordered a new Pro-4100 because so much of my work in artwork repro has been done on Canon's, and until this Pro-4000 unit, they have been reliable. I have an 8400 still going for at least 4-5 years now.
I spoke once again with Canon tech about the failed Pro-4000, and he said that "there's lots of sensitive parts in there, and sometimes they fail." And that is true. But complete failure after 2 years and 3 1/2 months is not a good sign. Maybe I just got a lemon. No offer from Canon of any help or assistance of any sort, or anything towards a replacement unit.
I'm not telling you what to buy or not to buy. I'm sticking with Canon FOR NOW because so much of my company's art repro work is set up and dialed in on Canons inkset and we run / have run Canons for years now. This entire experience runs contrary to what I experienced from Canon in the past. Maybe Canon is falling on hard times. I don't know. Anyway, I share here so folks in the biz will know and can use this information if you are considering a new printer purchase.