Canucks0: I own a DV-50S and for the past two weeks have been breaking in my new UX-1 Limited. All I can tell you is that the difference between the 50S and the UX-1 Ltd is monumental, both in the audio and the video sections. Mind you, I was very happy with the DV-50S and I use it just for redbook and for DVD-V (so please don't ask me about the other SACD or alphabet soup options).
I think the DV-50S is a stellar performer and a piece of gear that will last you centuries. But I had a great opportunity to get the UX-1 Ltd and I just couldn't pass it up. I'm sure that you want to hear a detailed review but my reaction to the UX-1, stone cold, right out of the box was just "oh my God! Wow!" I did the classic double-take... It's amazing how much detail the UX-1 Ltd can suck out of a little disc.
Now, some may consider that too analystic or "dry" or "uninvolving" or all those other nonsensical adjectives that are bantied about but (to repeat) "Oh my God! Wow!" is the most succinct way to describe the UX-1 Ltd (and I would assume, the UX-1).