I just received the R300 through Amazon. Phwoooooaaaarrrrr. Lovely sounding amp, but I am only a few hours in - keep in mind also that I got it to compare with my purely digital setup (Cambridge Audio 851N + 851W into PSB T3s) and I am only really at the beginning of playing around with my audio setup beyond speaker placement and room adjustments. As a newbie, I can wholeheartedly recommend this amp and price point at getting into tubes. My speakers are 91db and very easy to drive, and particularly as I am not a loud volume listener (except when I've had a bit more bourbon than usual) they are an excellent choice for someone like me.
First listens from this morning:
Esbjorn Svenson Trio
Hiromi
a-ha
Brad Mehldau Trio
Duran Duran
Amorphis
Jeff Buckley
Ghost
Ulrich Schnauss
Tangerine Dream
Initial impressions are that the dynamics are much more alive than with the Cambridge Audio - much better and more natural volume control. No surprises with a tube setup it is a much warmer and richer sound. Now to give it a couple of weeks of listening to get those tubes settled in.