Jeff,
They both work. I think the Pearl feet probably are a little more effective but both solve the issue.
I really learned my lesson with these when I purchased my 70's Premier kit. I tuned it up and held the floor tom by the rim and it sounded great; fat, warm and resonant with a nice, even sustain. I was looking forward to playing it so I installed the floor tom legs which had no rubber feet. The floor tom immediately turned into a flat cardboard box. That is when I ordered a bunch of Gibralter feet. I keep a drawer full of them just in case.