Old post but I'll respond. I post on copier forums a lot and we've talked about the 6250, same engine and guarantee I believe just faster. My understanding is they're very reliable.
Bad things I have heard is not the best on solid blacks.
If you're doing a maintenance agreement then this won't matter, but if you want service options from other companies or self service, Oce' and Xerox aren't the companies to go with.