I've owned my current 4900 for just a shade over two years now and printed about 1150 sq.ft. in that time period. The systematic pattern is that it must not be left idle for more than three days, otherwise at least one channel will be blocked. It's probably not "clogged ink", but dried ink on or near the surface, because a one pass one pair head cleaning usually fixes it. If left unused for several weeks, however, more channels are unapparent on the check pattern and more cleaning is required. Sooner or later, all the channels always comes back; the longest waste of time with this has been about 40 minutes. More vigilance is needed in winter than in summer because humidity in the room is lower - winter can be as low as 20% which is not enough, and I should run a humidifier, but this needs to be controlled for other reasons. Apart from this nuisance, the 4900 is the finest quality photo printer I've ever owned. It is built like a tank and the gamut, tonality, detail rendition and overall print quality are superb, so I put up with the inconvenience and will continue to do so unless major, expensive repair issues were to arise. My experience with the 3800 I owned before buying the 4900 was far better in terms of freedom from blocked channels. The question I would put to Andrew, however, is whether his 3880 delivers visibly the same print quality as his 4900 when it works correctly. I am asking this question with no particular motive in mind - it is simply to know the answer, just in case he has done such comparisons.