I use Klingspor, and I love them. Very good quality and price. the blue alumina zirconia seems to work well on epoxies without clogging. Anything worth buying is worth getting the box of 50. as soon as it gets dull or clogged, rip it off and get another. Time is more important than money.
I am intrigued by the new mesh abrasives, but I have plenty of other stuff to use up first.
I also bought rolls of various grits from Klingspor for the longboards, same thing applies here, the minute it looses it's bite, replace it, It feels so good when paper is fresh and working well.
I have bought their boxes of short ends and pieces, you get a grab bag of various grits and sizes. they call it shorts and pieces, and you might picture little tiny pieces, but their idea of a "scrap" might be a dozen 50' rolls, dollar for dollar, it has to be hundreds of dollars worth for maybe 20 or 30 bucks. Frequently, I find something in the box that is perfect for what I am doing, but I never would have thought to buy it.