Yes. It's an Eizo, so pretty stable, and I calibrate every two weeks. I haven't calibrated the printer, though I do use known papers with profiles for the P800.
Funny that I’ve had an iStudio calibration unit around for the past year or so and had never gotten around to calibrate my P800. I’ve tended to settle on Hot Press Bright as my standard paper that I use. Two days ago I finally took the time to calibrate the printer and compare it to the std Epson profiles for that paper. The difference between the two profiles was subtle. The iStudio profile was slightly more contrasty with slightly more detail on an all white bird. I preferred the iSudio version but when I showed it to my wife she picked the Epson version. She pointed out that the iSudio ver had a slightly blueish cast. I checked the numbers and it did. Adjusted the tone and tint to slightly warmer. Everyone was happy with the result. And I still liked the extra detail that I got from the iStudio profile.