I have found that the expensive ones do not last long enough nor cut that much better to warrant the cost. This is where we buy all our rolocs, flap discs, cut off disks etc.
http://www.lehighvalleyabrasives.com/servlet/StoreFront
You can't beat the cost. The only thing I recommend is pay attention to shipping. It's best to order multiple things to bring the overall shipping cost down. Even with shipping the cost is better.
In a pinch if we run out and we don't have a multiple order, we have a harbor freight store 15 minutes away.
Just my opinion and yes I have tried 3M, Norton, etc along side the others and this is what I found.
Good luck.
