I picked this up on eBay a few years ago for not very much and it's only now that I'm finally coming to terms with 5 strings. The bass has its problems but sounds fine and I find it very comfortable to play. I spoke to RMI about it: apparently it was a one-off prototype made in China which had some issues when it arrived and they bunged in some cheap electronics to get it going.
I've invested in fret-levelling, but am thinking of going further. The main issue is buzzing: I'd like to replace