spyder 4 calibration and prints still too dark

Last night and this evening I have printed over 25 large prints on Presentation Matte both color and B&W on the R2000 using Image Speciallists inks and my new 18ml Push Button Rest carts I am surrently testing. I must say the prints are outstanding and if I had to for some reason reduce my printer army to just a few, I would definitelly keep the R2000.