The Zebra Airfit Jell is a fantastic pen, and is warranting top five consideration (speaking of which, I need to post a current list). It is so well designed and so comfortable, I have used it for days on end at work because it is such a pleasure to write with. Now I did make one modification, swapping out the 0.5mm blue cartridge with an 0.4mm black one, but that really doesn't change anything about this pens performance. The grip design is very cool, featuring a layer of air under the rubber. You might think it is really squishy, but it is just the slightest bit tight, yet not overly firm. I really like the yellow orange body style, and the barrel design itself is very comfortable.
When I did my written review, JetPens was out of stock on all colors, but I see they have reloaded. At just $4.50 a pop I can see why they were flying off the virtual shelf.
P.S. - I noticed that I didn't highlight my highlighter test - oops!