I have owned both the 380S and the X-1. I was very pleased with the X1 and the sound was great. A lot of punch, almost coloring the sound though and I'm not sure a preamp should change the sound too much. The X1 sounded a bit richer in the bass and highs with less mid range. However the 380S was and is a much finer piece of equipment with a very precise easy to listen to sound. The Volume control is super and the sound has all the detail you want even at low dbs. The real draw back and deal breaker is the X-1 remote is a pain in the butt, and you have to use up downs rights lefts to arrive at putting the sound up or down and changing inputs. This makes it impossible to include in a macro on a programable remote. Primitive, heavy and stupid is the only description for the remote. The ML 380S is finer, easier to use and a wonderful sound that you just don't get tired to listening.
