Just to throw my two cents in here...we own 4 Xerox 700/770/700i boxes (mix of these three) and have been quite pleased with them. We also own one KM C6000. We purchased a Xerox 700 initially out of these machines and realized that there were a number of things that we didn't like:
1. Color consistency across the sheet for large solids (particulary lighter colors) was not consistent, inboard to outboard was not the same.
2. Mottling appears depending on color densities and sheet types that can only be minimized despite our Xerox technician's and a specialists best efforts.
3. While registration is not as good as our presses it's adequate for most of the work we run and is well within their 1mm spec, usually 0.5mm depending on stock. We run 14point digital grade stock through these every day and they do quite well.
4. Gradients created without good forethought in the design stage exhibit banding.
5. The outside edges of the print (i.e. on a 13" wide sheet, the outer 1/4" of each side) displays poor quality
There are probably some other things that we don't like but these are the major things.
After using our first Xerox 700 for a while we decided we wanted to purchase a KM C6000 for our next machine in hopes of overcoming some of these issues.
We were quite impressed with the print quality on the Konica C6000, gradients look better than our Xerox 700 and photos look excellent. However there are two major points that we do not like:
1. The print seems to exhibit a decided pink/magenta cast to it. We've calibrated with a spectro, created custom profiles, etc. to no avail. Our main problem with the color is that it cannot print a good red, we have one customer that uses red for their logo and expects it to look spot on, this machine will not print it, everything in comparison to the red on our Xerox looks orange or tan.
2. The other problem, and this is our main beef with this printer, is the poor registration it exhibits. I've been told by many people that it should be better than these dinky Xerox boxes but our experience with this is quite to the contrary. This is exhibited with any of the trays and any stock types (although some are worse than others). It has a tendency to "wag" the tail of the sheet back and forth. The front of the sheet usually holds pretty well throughout the run but the tailing edge moves up to 1/8" from inboard to outboard and registration is quite shocking on this end of the sheet. Also in regards to registration we can go in and program custom sheet types with custom alignment profiles linked to the type, these never stay for more than a day or two (possibly between loading and unloading stock several times). I don't mind spending several hours setting up custom alignment profiles if they hold but after doing this for the nth time and spending hours setting up stocks alignments I find they are rather inconsistent and so we've resorted to simply spending an extra 3-4 minutes on each job to get it lined up adequately. We've brought this to our vendor's attention several times and even had a specialist from Konica in to look it over. They've replaced every registration / alignment sensor and part on this thing (so I'm told) to no avail. It exhibits the same behavior. Perhaps we just have a lemon.
In contrast the alignment profiles on our Xerox work quite well. I find myself tweaking the alignment for a particular stock once in a while (perhaps monthly) but by and large when I load Carolina 12pt C2S stock in Drawer 7 and choose our custom paper type with the correct alignment linked I can expect to get near perfect front to back registration. Text weight stocks tend to wander more but are reasonably close on the first print out.
So while overall I agree that the Xerox 700 series has it's problems and weaknesses we've been able to work around them. We've also realized that their are weaknesses with the Konica and also work around them. However given that we originally started with one Xerox 700 and one KM C6000 and now own 4 of the Xerox machines you can see which we prefer to use for most of our work. The Konica certainly has it's niche in our shop but it only runs about 5% of our color digital printing work.