OK - I'll bite.
I have an RM-500, and have gigged out with it several times, as well as using it at rehearsals, etc. I have used it predominantly with a Hartke 112, both with and without a Peavey 118 cab (for larger spaces/venues).
LOVE the features - incredible control of your tone and great versatility. I'll vary between a very sterile, metallic 80's bass tone and a warm, edgy sort of "Roundabout" tone, and the RM-500 handles them both equally well.
Fair warning: this thing is loud, and I mean LOUD. I had rehearsal with a completely mental drummer and half-deaf guitar player and still didn't need to turn it above about 2. Made my fretless just *sing*.
At the end of several hours of ripping on bass, the amp wasn't even warm.
So far reliability is 100%. Not a glitch, not a hiccough - nothing. Does exactly what it's supposed to do, gig after gig, and sounds great.
My $0.02. YMMV. Hope this helps.
- Kurt