You may find it very difficult to find the X series brand new- it has been discontinued for too long. I searched for one everywhere before I got lucky. Even then I only bought it because it was half price and I was bored of waiting for the Z series to arrive. But you know the thing isn't perfect. That 'warmth' means it is great with older recordings but pair it with a coloured amp and phones and it may be a little too warm for its own good. For example one of my favourite albums to listen to is Madonna's 'Ray of Light'. This recording is rich in the mids with lots of effects and little treble. The 'X' loses out on just touch of detail. But....listen to any track recorded in the 70's and 80's or rock and the thing is sublime.
My opinion is that if you have really neutral headphones the X shines. But if you don't then I would definitely try before you buy. I haven't heard a music player yet that excels in ALL areas, there is always a compromise.