As a former LexJet person, I provided technical assistance for every brand of printer. I'll give you my opinion and you can form your own based on the advice you get.
-For fine-art printing, get the word HP out of your head. The quality is nowhere near what Epson and Canons can produce and their drivers are clunky and outdated. Just a hassle. HP has stated to me multiple times that they have no interest continuing in the aqueous market, their focus is on the Latex, as well it should be (the latex printers are awesome.)
-Epsons are great printers. For the most part, they stand up. There are people who have issues with them, and if they're older than 1 year, it's pretty much a $5000 paper weight if something does go wrong. Your ink-cost UPFRONT will be less expensive, but bear in mind the Epson printers only have 1 head that clogs often. You'll burn through ink during black ink switches and clogs WAY more than any other brand, they also have smaller maint. tanks, causing you to purchase them more often. With all of that being said, their quality and DOT control is ALMOST unmatchable. They credit this to the Peizo printhead because they can control the amount of current that forces the ink out of the nozzle. Although, as far as noticeable quality differences go, there aren't many.
-Canons. Well, when I left LJ to do my own thing..I bought a Canon, an 8400 and I couldn't be happier. A lot of the problems (aside from hardware errors) people run into were generally user error, the quality is just as good (if not better in pantone matching) than Epson and the price...oh the price. The Canon comes with over $2000 worth of ink, and yes, the cartridges are more expensive upfront, but take into account you wont be cleaning it as often (compared to epson) and no ink waste when switching blacks (or time waste) and the cost of ownership over the life of the printer averages out to be comparable with the Epsons. Also, Canon has much better warranty support than Epson does. I've had customers get out-of-warranty parts replaced by Canon at no charge on a regular basis.
Just my opinions from the inside. I've worked extensively with all brands.
Name is Ryan King, I was the Midwest Regional Sales Manager in the Digital Photography dept there. I may know some of you!