Does any one have experience with a high-end amp switch or the Luxman AS-55

A switch such as this, no matter the quality, will decrease detail, damping and overall sq, in my experience. Several high end dealers I worked with, used switching in the lower level sound rooms, but never, in a million years, would use switching, when using the better higher end gear. I would not use it.

Well, like it or not, a lot of japan made high end amplifier come with built-in speaker selector! Convenience vs compromises :)

I was honored to hear from the designer of the Comparator at Van Alstine Audio, and read a few reviews and blogs about the unit. Seems like a great Hifi fit for my needs. In his words,
“A lot of effort has gone into making the ABX box transparent. It is DC coupled from input to output, so there are no coupling capacitors in the design. The only thing in the signal path are relays and an Analog Devices digital potentiometer, which is defined in the Analog Devices data sheet as a "digitally controlled variable resistor". The relays are high capacity 10 amp units, which are many times what is encountered. The digital potentiometer is a necessary evil as it is absolutely imperative that any valid comparison be made at the same volume level.” — Dan Kuechle 

Beresford makes a quality line of amp/speaker switch selectors that are both affordable and provide dummy loading to protect your amp if you forget to turn it off when switching. 
http://www.homehifi.co.uk/S/selector.htm

J.Chip