Nick,
Keep in mind that my comments are all relative to my experience with the HP 450c and that we are not a production house. Nor do we do a lot of color-critical work.
Overall, we are very satisfied. The quality is good, the ease-of-use is good. As we upgraded from a single-sheet feed, non-cutting unit to this one, there was a very small learning curve.
I like the way single-sheet feed behaves. There is essentially a vacuum system which holds the paper in place as you align it. Loading sheets seems to work better (faster, easier, more forgiving) than the HP 450C's method. But that is to be expected with any newer printer.
The roll feed is also easy to use, but as the manual outlines, it is rather imperative that you mount the roll correctly. We had a minor issue with roll paper which seemed to be misaligned on the tube which in turn caused it to not fit on the spindle correctly (tightly). We could not get the plotter to accept it. The problem was eventually solved, but we had to play around with it just a bit - really making sure the spindle had a good tight fit. Was not so much a negative experience as it was a learning one.
We did find out how to remove the border from the overlaid objects. Minor thing, but was good to find. Seems as though it is a universal setting, so when you turn it off for one object, you turn it off for all.
Our standards are pretty basic. We create courtroom diagrams and will occasionally enlarge 10MB pixel digital photos. As far as color control, Postscript functions, output to different paper types, etc., I'm afraid I cannot be much help as we have not addressed those issues yet. We do not use the photoPRINT software so I cannot assist you there.
The printer does NOT have a hard drive, nor does it have a lot of RAM, and thus relies on the computer to stream the print jobs. We found this rather odd, but were assured that we really wouldn't see a hit on system performance. From the small number of basic files we have printed, that has indeed been the case. Jobs seem to get there very fast and start up right away.
Installation was easy, but will take two people at a couple of junctures. Driver and software installation was as easy as it should have been. We have it hooked up via TCP/IP and that works well. The printer did not seem to be automatically found right away, but as we wanted to assign it a static IP, we did that and there have been no problems. The printer driver's "control panel" is sufficient. The printer itself has an LCD panel which, despite being small, is rather informative.
As a general plotter, we are quite happy with the unit. We were fortunate enough to see it in action at Charrette in Woburn, MA. That, (and a lack of negative online reviews) was pretty much what sold us on it.
Hope all that helps,
John