Here's an interesting story about my 7900 which I just finished saying behaves well:
My LK cartridge was running low and I got a message saying that a cartridge was too low or the waste tank too full to run a cleaning cycle so I selected No to the continue cleaning prompt. I then printed out a nozzle pattern and it was perfect. So I call Epson and ask why and their solution is to turn off the auto clean feature which I did. Their answer to the obvious question of how will I know if the feature is broken if it is turned off was basically to watch the printer for any other cleaning issues and call back so they can build a case for a service call. With the feature off, a few prints later I get the message again to which I reply no and decide that maybe I should just change the cartridge figuring maybe a low cartridge is causing a problem (hadn't got the cartridge out message like older printers - does the 7900 do that?). Much to my surprise the cartridge gave an error message so back on the phone to Epson for an overnight replacement. So I get the cartridge, put it in and the printer starts up fine. Go to print a nozzle check and the printer tells me to please wait for a cleaning cycle (?). Then it prints the nozzle pattern and lo and behold the nozzle print shows gaps. Back on the phone again to Epson where I ask why after a cleaning cycle are there still gaps to which I got the reply that sometimes there still might be gaps after a cleaning cycle and I need to do a cleaning cycle myself. So I said OK, I should do a selective channel clean and call you back if there are any more problems (after reiterating my concern over the auto cleaning feature which they had me disable) and he replied Yes Sir, have a good day.
I must confess I am a bit frustrated at this point...
Jim