I have an XpertJet 661UF as well. After years of using a DCS machine it has been a great upgrade. It does use lots of white ink if sitting idle, the upside to that is it does a self cleaning process so the white doesn't get stuck in the head. You lose some ink, but having the machine print ready without a ton of initial charges and head cleans is worth it for me. White ink is a pain no matter how you cut it you are going to lose some. Best thing to do is just run the heck out of it!