Pros: Comfortable Grip, Glides Smoothly, Ink Dries Quickly
Cons: ink smears on some surfaces
I love these pens. I discovered them a couple years ago and use them for almost everything. They are comfortable, write well and smoothly with no ink gaps that you have with other pens, refillable, inexpensive enough to lose, and come in tons of funky colors.
Regarding smearing, on regular paper you have to give the ink a few seconds to dry or it will smear a bit. But on certain surfaces like on the back of a credit card or on the thermal paper folks use for credit card receipts the ink will smear a lot until it is dry, and it takes longer to dry on those slick surfaces, even when you blow on them.