Before I sold up and became a full time roadie, I had a Bos Vipr on my Nicolai Helius AM.
I thought it was excellent and that was coming to it from a CCDB coil as well. I had zero issues with it on a mechanical basis and it’s performance was excellent especially in more extreme terrain.
At slow speeds (shaft) speeds it did used to sound a little asthmatic and without the harder compression dial in the ‘on’ position, it didn’t inhibit pedal bob quite as much as the equivalent from other companies, but as soon as you picked up speed of fast rough ground, it was brilliant in a ‘fades into the background’ kind of way.
You’ve got options for support here in the UK other than the official distributor (whoever that is now!)