The problem with buying a TRL amplifier is that it's virtually impossible for a customer to hear one before buying it, and there are virtually none available on the used market to allow a "Buy-It-And-Try-It" approach.
Now, I know the response to my comment is going to be that once you hear a TRL amp you'll love it, or that no one who has ever bought a TRL amp has sold it.
It still is an issue that a potential TRL customer must confront, and it's an issue that's not unique to TRL either.
I guess I have a barrier to buying on faith alone.