Who makes most agressive 8x3 dia. sanding belts?

In using a few different 8x3 inch sanding belts I have noticed a
difference in how quickly and smoothly the belts sand. None of the
three different belts that I now have are from the same company. I
just bought them one at a time as needed. What I have noticed about
the last belt that I purchased was how aggressive it was. It is a 320
grit belt that comes from a company in Florida. What I am wanting to
know is if this company might have the best belts. If so, I want to
get more of them and in different grits. What experience has anyone
else had with diamond sanding belts. Which belts seem to be the most
aggressive for each of the sizes from 220 to 600?