Jan, one of my friends has some of those high priced wattgate outlets that he just raves about, saying its one of the best upgrades that he has had in years. He told me that your never know how your stereo system can be until you use good outlets for your whole system. His system does sound a lot better with the wattgate outlets in it. On a few other forums some are raving about these new maestro outlets saying they are an real eye opener.
Plug some of his stuff in to another outlet using a cheap extension cord and see if he still raves. or thinks something is 'wrong'. Leave the amps alone. Only low power stuff to be moved. Make SURE he is NOT LOOKING.
I have no doubt about increasing the quality of the incoming power flowus interruptus.
However, i will note that just replacing old sloppy recepticles with new ones makes a big 'ol difference. Using cryo'd 'hospital grade' outlets is fun, I bet. 'Hospital grade' was first determined to be explosion proof in an oxygen rich environment, in a hot-swap scenario. If this is an advantage to you, along with a 20 amp rating (standard 14g will not fit into the quick inserts) and a wonky sideways plug, then cool.
My friend has some of those high priced wattgate silver 381ag outlets he just ordered some of these maestro outlets. I will let you know what he thinks about them.