i have a lot of stuff from both manufacturers - including the cones and the Lampblack Ball, Iso-Cup and Hi-End Base
really no comparison between the two in terms of how they work - the cone is simply rigid. the Isos set up with the lampblack ball are unbelievably slick and seem to work much more like an aurio. too much cable tension can be an issue
the Iso would definitely be my choice under anything with a motor (CD, BluRay etc) haven't ever tried them under an amp
if you go with the cones and like the effect, you can add the "Things" or the "Pits" for even more isolation. This might be the best way to go with a heavy amp.
all that said this is one those get them both, sell the one you don't like kind of deals - lots of variables starting with what the amp is sitting on
