I have the same problem as the TS, two amps and one set of speakers.
Untill now I have been switching speaker cables when I wanted to listen to the other amp.
Having read about these 4PDT switches it seems like a great solution.....so thank you for starting a topic like this
These switches come in on/on and on/off/on (or on/none/on) variations.....might be opting for the ones with an off position to avoid possible contact problems during switching.
On to Ebay now for some switch shopping :-)