I appreciate your efforts to help people with clogged heads, Jon, and wanted to offer some counter experience to what you have posted regularly about how 9900 heads are failing widely.
I have been using ConeColor inks since we got our Epson 9900 and, perhaps, this is the reason, but it has operated flawlessly now for a number of years, not yet a single incident of a clogged head. I have actually had more issues with refillable cartridges and refillable cartridge chips than with the print heads.
When I first got the printer, largely based on your warnings, I purchased a set of empty cartridges and a large container of piezoflush and they are still sitting on the shelf years later. I'm glad I have them and I am also glad I have not had to use them. I also purchased an extended service agreement that is nearly ready to run out to the tune of $1200.
I have a handful of friends who have had the same good experience with the 9900.
One friend, a professional photographer and giclee printer, workshop leader and teacher has been using his 9900 printer for 5 years without a hitch.
One thing I do religiously is to print something regularly. If I don't have a job in the hopper, I simple print a test image daily. If I am not going to use the printer for a while, I put in a roll of inexpensive narrow 24 lb inkjet paper and use a launch agent plist (I'm on a mac but Windows must have something similar) to run a script to print some small image daily. This keeps the heads wet. The thing I have heard from any number of people, printers, repair folks and service people is that the killer of heads is non-use.
I'm not posting this info to be argumentative, but I did want to let people know that some people have had great experience with the Epson 9900. It does have a lot of nice features not available in previous models.
If I remember, your first experience with Epson clogged heads was with the 7900 rather than the 9900. Of interest, a professional photographer I recently ran into who was leasing both a 9900 and 7900 from epson had had big head clogging problems with the 7900 but none with the 9900. I wonder if there is some difference regarding head issues between these printers.