There are three things you need to consider before buying a guitar distribution system:
1. The sound
Will the original tone of the guitar shine through or will it sound like you have converted the guitar from passive to active. Loading is also a problem as your guitar will have no balls. You must however compensate if there is 'no loading'. If not the guitar will no longer sound right. This is important.
2. Isolation
You have to make sure the amplifiers are isolated from one another or else you will probably have problems with ground humm and buzz. Also, be very careful when using older amps that do not have 3 pins as this can be dangerous!
3. Control
Make sure you can reverse the polarity, lift grounds and turn on and off the amps and effect devices as needed. Changing the polarity (phase) can be huge!
One other point...
Reamping is great fun!
Record a dry track and then send the signal into your amps afterwords.
