i've been thinking about getting the isolation pads myself.
i've got primacoustic foam on my walls, and i heard a definite improvement in the sound of the room
HOWEVER,
when i have my amp on the ground, the carpet muffles the amp, so i always put my amp up on my old wooden school chair. i don't know if having it off the ground is what makes it sound better, or getting it off the carpet.
i'm gonna get it anyway, they aren't expensive, if i don't like it i'll sell it on ebay.