It's always a good plan to know what you are getting yourself into when it comes to "upgrading". One thing I can say for the new x900/x890 printers is they are much faster then the old 7880/9880's. There is no difference in print resolution though and they do tend to be "troublesome" with frequent clogging nozzles.
BUT, we have several customers who have reported good success rates with these printers, these are customers who use their printers daily, keep the humidity levels stable, agitate their carts once a week & perform regular cleaning on the flushing box, Capping Station, Wiper blade and bottom of the print head. We do recommend avoiding Power Cleanings on this print head, too many in a short amount of time can damage the head, it is best to keep the printer printing on a regular basis to avoid clogging.
In addition we always recommend purchasing the extended warranty with these printers, it's a good chance you will have to use it after the 1 year manufacture warranty has expired.
We use the 7880's & 9880 in our studio and they are remarkably reliable, we are always on the look-out for used ones, if you do decide to replace yours, we might be interested in purchasing it from you.
Hope this helps in your decision making process, Kelly