I bought some for my Freedom Collars just because on a long marathon pulling a heavy pair carriage I figured a little extra "squish" wouldn't hurt, but the pads did not fit the FC at all so I sent them back. Friends have ordered them since and been equally displeased with the shape of the pad not matching the Deluxe/Freedom Collar.
I do, however, have Pillow Pads for my straight breastcollars and for under my ComfyFit Sport Harness Saddles. I like them because they are unobtrusive and thin (so they don't affect the fit of the saddle which already has graduated padding meant to lie flat against the horse from top to bottom) but they keep the saddle clean and help it sit up evenly on the horse's back rather than being drawn down forward against the withers as I've noticed sometimes happens when I use the saddles without them for dressage. The breastcollar pad sometimes seems to chafe the hair a little bit when they're in winter coat but is excellent in summer and I've never had a problem with the saddle pads no matter what the conditions. I much prefer them for cushioning a well-padded saddle or simply adding a little "give" to a stiff straight breastcollar on a sensitive-skinned horse. For a saddle that has insufficient padding of its own (like most cheap leather mini harnesses) I prefer the thicker pads as they're actually needed.
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