For cutting 5" pads, if you are using a DA other than the Flex, but for polishing, glazing, sealing, ..... I'd use 6" pad. The bigger footprint will get you there faster.
I like HT pads better, but I must admit the other pads (flat or CCS) last longer.
The flat pads are a lot better for a beginner. If you don't use good technique with the HT pads, they will be toast real fast. That said, they correct beautifully. Not better than MF, but they finish better.
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