Morning Adam
IMO up to now it's the best combination I've heard with Raidho's. But that said I haven't heard the new Aavik separates. Tyler asked me if I want to 'break in' his separates since his store isn't open yet and I refused for fear I wouldn't want to give them back. If I did give them back I'm afraid I woudn't be as happy with my U300. Lars had mentioned before it was released the separates adds many more layers of resolution. Another amp I really liked is the Burmester 911. Definitely a warmer sound with unbelievable control.
That said I've read the Raidho's sound best with amps that have a high dampening factor. The Aavik is about 8K - the Soulution about 10K and Burmester about 14K.
You should send a pm to Le Roy and if he is still in town I'm sure he would invite you over for a demo.
George