Rod,
There are some really great technologies out there today.
For lower power supplies (under 30v), Tripath is a great choice. It's powerful, can be bridged, and has a very musical sound. The new ONE.3 amps will run from 18-31v which is the sweet spot for most power technologies out there (ie. from laptop brick to batteries, etc.). Almost every aspect of the amp is tunable - from power to input caps to POTs, etc. It has non-linear qualities like tube amps (not necessarily the same qualities) which some people like. I do.
For more "umph" and analytical sound, higher voltages help. The IRS2092 is particularly clean and hard-driving. We had a "bake-off" a few years ago and it was very impressive with stock supplies. But if that level of clean, brute output is the goal there are now some even better if pricey options: ICEPower, NCore, Tommy's Cherry's, THX (new). We'll try to offer something high value in the future.
In this arena, the long pole in the tent is power supply noise, and that's where I think the Tripath has a hard time keeping up. The old Bel Canto Tripath amps were amazing. And they weighed 60 lbs each because of the amazing PSU. To some degree you can buy your way around the problem with batteries and big torroids.
It's a great time to be a buyer in this market and an even better time to start looking into the high-sensitivity side of things where there's more diversity in offerings (low power tubes, high sensitivity horns, etc.).