on your needs/usage. Want a multi-purpose printer, meaning some photo printing, some document printing, a little of this and a little of that? Do you value speed of printed documents over quality? I'd suggest googling "[model name] reviews" for both; look for reviews from forums dedicated to printers. And I'd go to a BestBuy or some store where you can actually test the printers and judge for yourself.
I've always been a big HP fan. I still use my 4 yr. old HP 712c for document printing, and the thing is still going strong. It also prints VERY nice "near photo-realistic" pictures on glossy paper. About a year ago, I bought a Canon i960, 1 step below their top of the line home consumer printer. Use it for printing pictures only, and you can't tell the difference of a printed pic from a film print. So I have the best of both worlds. So if you already have a printer that still prints documents well, for example, and want another printer for better pic printing, I'd *generally* say go for the Canon (didn't look up specs of the ip4000.) Canon picture printers use thousands of print nozzles as opposed to HP's and Epson's hundreds, that's why the pictures printers *generally* are much better. Depends on the model, so check the specs.
2 quick google reviews: http://www.pcadvisor.co.uk/index.cfm?go=news.view&news=4300
A quick look at both, I'd go with the Canon. JMHO. Your choice. Still, I KNOW my HP is a workhorse. My Canon is less than a yr. old, so I can't comment on Canon's long term durability. Good luck!
which is the best?? They have the same price?