Hi,
I've shot a Limbsaver on an 870 Express (factory synthetic stock) with 3" waterfowl loads, and while it wasn't as comfortable as an autoloader, the pad did a pretty good job of taming the bite compared to the factory pad on the same stock on my own 870 Express. I've got a Kick-Eze on an upland bird gun, a 20 ga L.C. Smith SxS, and you can barely feel it go off compared to the traditional Pachmayr pad it had before. But I've never been able to do a head to head with both pads and one gun, so for now I can only say they've both worked well for me and one probably won't go wrong with either.
Rick C