This isn't an interesting discussion as of yet, so let me throw my $.02 into the ring.
If you were to ask me about Canon or HP inkjet technology 3 or 4 years ago, I would have told you that Epson was the 5,000,000 pound gorilla that threw the other guys out of the ring. As of this moment in time, I think all 3 players have very viable products out on the market and the quality gap is very very close, depending on your own specific needs or sensitivities. As a guy that has all 3 of the latest 44" printers (Epson 9900, Canon iPF8300, HP Z3200), they are all good a different things. I think it comes down to usability, access to support, TCO, paper handling, etc etc etc.
I think there are more anti-Epson folks on this forum than die hard supporters, primarily because I think Epson didn't have the right large format products on the market for a long time (switching of black inks was a huge pain until the 7900/9900 models came out), and also because of clogging issues. The clogging issues is an interesting one, because on the thermal heads on the Canon and HP models there is still clogging, but with more nozzles you never know about them until the head has died. The replacement cost is much much less than the Epson, but it is still a cost and hassle.
As an independent guy who happens to create profiles for an inkjet paper company, as well the running of fine art digital printing workshops, I need to own many different printers on the market. We are living in good times right now, as the quality of these products is quite high and costs are coming down (especially with the Canon and HP models). What's not to like?
Personally, I don't enjoy printing on the Z3200 due to speed, paper handling (rear paper loading is a pain, as well as cut sheets), and I am very happy printing on the Epson 9900 and Canon iPF8300. The new Epson 4900 that I obtained this week is a dream when compared to the Canon iPF5100, which I won't even bother turning on. Too bad Canon and HP don't have an answer to the Epson 3880, because more competition would be a good thing.
I added up the number of inkjet printers I have, and it is kind of mind numbing:
Canon Pro 9000 II
Canon Pro 9500 II
And I have access to the Epson 4800 and 4880 at my assistant's home.
Ok, this is getting long-winded. /out