I recently had an issue with my DAC and, to reinforce your own experience, the support from NJC was absolutely outstanding. They have basically replaced the entire unit FOC - no quibbles no awkward conversations, just great customer service. I can't speak highly enough of them.
I may, however, look to replace mine very soon and am pondering what to replace them with. The only reason is that the USB on the DAC doesn't support hi-def (I think) and an increasing amount of my music is 24/96. I am not a big fan of optical so am currently looking for something of similar quality and form factor and preferably in a one box solution. I'm struggling as replacing NJC stuff and meeting those criteria is not easy.