sorry to disagree here.
I have been using CISS systems on all epsons,( and brother printers ) small and large, and never have i had any problems with them...not one ;).
They need to be set up 100% right from the start....CISS must be primed, and primed right before you start.
Do that right, and it should never give any bother
refillable : PITA to fill, in or out machine - if one is busy, these refillable carts are a big NONO...as you are topping them up every 3/4 days..been there, done that