Also has a lot to do with cooling. Some BP release heat a lot more due to the type of foam it's made of. I have a 5" Meg's BP and I love it. Is it the best? Definitely not, but for the price compared to some others it is nice and has never let me down. If you look at
www.buffdaddy.com it is owned by Kevin brown iirc. He has some wicked awesome backing plates, but they are rather expensive. Mirka makes the cool looking plates that he sells. Their plates come with holes in them to release heat from the pad to help prevent the velcro from delaminating. Is this overkill? Probably, but with the price of pads, every little bit helps to protect them.