I have owned a 390 for a couple of years and have been very pleased with its sound. I tend to be a tweakaholic, and the Moon 390 has never failed to reveal the most subtle of differences in my explorations.
Customer service is excellent: prompt, personal and knowledgeable. Who can beat a 10-year warranty?
Judging by the positive reception of their new 800 series, you can be secure that Simaudio will be here for another 40+ years...