I spoke with Kodak support people quite a bit during that time and they always gave me the impression that Kodak was not giving them the support they needed to keep up with demand. The ML-500 at least seemed to have been hand-built, and when I called in because it stopped printing yellow or whatever I would often end up speaking to one of the actual engineers. Great for figuring out what was wrong with it, but it seemed really weird that these guys were seemingly fielding calls all day.
The main thing I remember (other than the printers broke constantly) was that after a few years it became next to impossible to get media for it- we'd call our distributor and he'd say "I don't have any this month, try xxx." So we'd call them and they'd give us another lead, and eventually we'd find some and order as much as we could, and then start the process again the next month. We always assumed that most of the stock was reserved for kiosks.
I'd love to hear more about what was going on with that, if you know.