My X7II stopped working one day and I am worried about the warranty. I sent it back to the factory and am waiting on getting it back. If it weren't for that, I would say that the sound is very, very good. I also have a X5 MkII I now use as a DAC for my computer and laptop. I also have the A5 portable amp, but haven't auditioned the AM5 module. I also haven't sampled the x5 Mk III either. The x7II is MUCH better than the X5 Mk II, I can say that for sure.