I had a RD5 for a while a few years ago and it was pretty damn cool. I did get a chance to play the RD20 for a few minutes a while ago and I really liked it. Even more than the 5. Real nice clean too. If you don’t need/want a clean channel, the 5 or even the RD1 would be cool. The single tone knob combined with the three way toggle is surprisingly versatile.