Ed may not like this one, (love ya Ed) but I've almost entirely stopped using the Easyflow9000s, and stopped offering them as an upgrade. I write a LOT at work and there are certain documents that require no mistakes whatsoever. In the last couple years they were skipping, and that was a problem. They would skip more frequently when they were being first used (like the first letter of the first word) after sitting for awhile, and I was having to completely scrap some paperwork due to these small errors and start over.
I thought it might be a bad batch so I ordered them from a different source, then another and another, including ExoticBlanks, though theirs were slightly better functioning (mechanically) due to having no label.
Here have been my personal observations and frustrations with Parker refills:
Easy flow: Looks nice and feels good but skips. Also more prone to smudging.
Standard (Dayacom & whatnot): Don't skip or smudge but look like a cheap bic, ie: faded looking, less smooth requiring more pressure/effort, etc. And as others have mentioned, they have a shelf life.
Gel: write good look good feel good….run out in like a week at my job. As opposed to months with ink refills. Also more expensive, which is not a convenient or sustainable combination for me.
Here's the good news and I have NO idea why I haven't heard more about it. The Softline. It writes super smooth and super reliably. It doesn't "look" as good/dark as the ink from a gel or easyflow, but it looks fine. I literally don't think I've ever had even a small skip and that's something I've never experienced with ANY other refill. This is now the refill I use exclusively for myself and offer as an upgrade, and I buy them by the butt load from ExoticBlanks. (Now hopefully Ed isn't as disappointed in me

)
I also order probably 80% of my kits and supplies from EB, only going elsewhere when something is out of stock or for the rare mega sale or something. They're the best.
But yeah, I'm off the easyflow train.