I am open to new ideas on the Cross refills. We have an upgrade refill. It is said to have a greater capacity and write longer---but I have no real way of judging. As to the "writing experience"---Unlike the 9000 that I can immediately tell the difference, with the cross substitutes, I have to switch from one pen to the other a couple times, then identify the "upgrade".
IF someone knows of a better refill---I am certainly open to handling it.
FWIW