I’ve been using one for a few months, and like it a lot. It’s a unique instrument with a lot of possibilities. I love the timbres I’m getting out of it. Unfortunately, they’re only available as pcb/panel/frame sets, so it takes some work assembling all the parts and doing the (tight) build. It’s a lot of circuits in a small package, so I would have preferred a larger version, but once you get used to it, it’s reasonably playable.
It’s at the intermediate level of diy builds–the pcb is deceptively small, but you’re building a full synth. Mostly through hole, but a non-trivial number of SMD components. THC had some aesthetic ideas that go against the grain of sensible diy design, but anyone who’s built at least a few modules or other types of kits can likely finish a successful build.
The strengths are the interesting normalled signal flow with multiple feedback loops, and the dual PT2399 delays. There’s some similarities to the Make Noise Strega, but the RM allows you to break any normalling and patch the complete signal flow any way you like.
Here’s my first track made with the RM. It’s 90% one recorded pass, with a a small number of samples from other recordings added in post.