My system is tri-amped and I wouldn't have it any other way. It is a worthy pursuit. I use four Pass Labs amps, 2 X260.8 mono-bloc amps for the woofers, and one each XA30.8 for the mids and the tweets. The amps never get out of class A no matter how loud I make it or how high a peak demand may be.
I believe the biggest advantage is that the mids/tweets have no idea what the woofers are doing. Yes the run a little hot, about 107 F.
An ARC Ref6 goes into a custom Marchand electronic x-over and out to the amps. Marchand has you pick the slopes and x-over points. They can be changed by ordering small pc board plug-in modules. The front panel has level control for bass/mids/highs for each channel. Very handy. Fun to fiddle with for a while, then I've found what I like and "usually" don't touch it anymore.
The source is all digital and the speakers are Hartley Reference (no longer available).
I haven't been everywhere but I have not heard anything better. Its out there but I have ceased to look for it. This is my end-game system.
Regards,
barts