I want to purchase a 3" and a 6" rotary backing backing plate that I can use on both my rotary buffer and use it on my PC DA using the rotary-to-DA adapter. I am undecided between the Lake Country rotary backing plates or the Flex-Foam HD backing plates. I know the LC are urethane based while the Flex-Foam is obviously foam. Any recommendations on which ones I should buy? Thanks.