I agree that you should not have all that gear between the speakers if possible. A lot of times it's not possible though and you have to work with what you've got. It's quite amazing how much difference you can hear though when you move your racks out from between your speakers.
As far as isolation of the turntable. Pretty hard to beat the vibraplane.
As far as isolation of the turntable. Pretty hard to beat the vibraplane.