In it's price range, probably the best you can get. I wouldn't worry about replacements making it obsolete - the K3 inkset with Vivid Magenta will be around for many years to come and any "new" version would probably show only minimal improvements with a fancy new price tag If quality is your main concern, you should probably be looking at a 4880 or one of the bigger pro printers anyway.
Chris, the 3800 does not use, and is not compatible with, K3 with Vivid Magenta. It uses the K3 inkset previous to the new magenta, and thus is two generations behind the HDR inkset used in the x900 series. Not that this means that the 3800 isn't a great printer and a great bargain. I used to own one and liked it quite a lot, though the lack of roll support proved to be too much of an inconvenience for me. If one's work doesn't exceed the gamut of the 3800's inkset, then this isn't a relevant consideration. If it does, then the newer inksets are a valid consideration, depending, of course, if one's files have gamut requirements that correspond with the extensions of the newer inksets.