I'm gonna be working on a metal mix right now where the guitars were tracked with an rb500, I'll se if I can get clearance to post a sample.
It sounds ok, it's a bit muddy though compared to an r121...

but I think it's definitely useable.
It sounds nice on clean guitars but lacks the definition I think for heavily distorted ones.
I haven't done any processing so you guys'll get it as raw as it gets

.