I purchased the hp500ps based on the recommendation of 2 architects who owned these machines.
However, I have been disappointed with my purchase on about every imaginable level.
Not only is the machine awful but so is the service and software.
Check out their user forms to get an ear full of complaints including the fact that hp keeps removing their (valid) complaints so others won't see them.
Hp will constantly bother you for an extended warranty that costs so much you may as well buy another printer instead. Further, they ran out my warranty replacing parts and stopped trying to fix it even though it was an ongoing problem.
Oddly, my buddies say they don't have printing problems, but after seeing one of their prints I have to conclude that they accept very low standards of print quality.
Now if you insist on buying the hp, I'd be happy to sell you mine so I can buy the epson.