I ran the 390 in my system for about three years and still have it, even though I’ve replaced it with a hybrid preamplifier and a dcs dac streamer
I also use a simaudio phono stage. My experience with the brand in general, and the 390 in particular has been very positive. Very solidly built, reliable gear and well designed software.
I think the 390 offers great value for all it does. It’s an all in one that offers good sound quality. I agree it is “neutral” but I say that as a positive. The 390, to my ears, was never overly bright, sterile, analytical or any of the other perjoratives that sometimes can be mistakenly conflated with neutral. It delivers a faithful reproduction of the signal it receives, at least that’s my impression. Good soundstage, detail retrieval and imaging.
I also found the 390 to be completely reliable. Used it for about three years without a bobble.