Circa 1995, I bought a Kenwood cassette player. I thought it was so good, I was like telling everyone, zOMFG, it blew everything else out of the water. Nothing can compare to Kenwood! omfg omfg! See a pattern here? XD So perhaps I'm just bitter, but I think Kenwood might just happen to have a very pleasing sound signature, more than anything else.
There's no demo unit of the X series in taiwan yet, not for another 2-3 weeks, so I haven't heard it. The concensus on Japanese forums though, is that it sounds very different - as in the sound is not as "colored", not as "juicy" as earlier Walkman MP3 players, but the absolute quality is higher. In this sense, it seems as though it would be great for the music you listen to.
I don't know if you're a stickler for background hiss. Some Kenwood models and the X series both have noticeable hiss, which is not going to go down well with certain very hi-end phones (mostly the SE530 I think).
If you are thinking of buying Kenwood players, avoid SCL5 at all costs; the hiss is said to reach untolerable levels.
With that said, it would be better to state your budget, and the type of OST you listen to. "OST" alone does not qualify as adequate description of a specific music genre, and it can be vastly different to classical music.
TF-10 pro and ER4 would be your best choices for classical music.
And if you are buying Kenwood, make the effort to get lossless format instead of mp3; your ears will thank you.
sorry ~~ maybe i should tell you more detail , actually i will use my mp3 player listen different type of music ,OST is one of the kind , japanese pop , new age , classical of course chinese songs and english song as well ~~ but i really think is hard to find a perfect match , course when you listening pop you need more base but when you listening classical which you need is totally different~~ so is hard to find ~~~
really that kind of match??? cause i have never use Westone before ~~~ but i have used audio- technica and sony ~~ their sounds qite good but sony too much bass for me , when you are listening j-pop is great but if you use it to listen classical and opera it seem~~~ if um3x compare with ck100 which one is better???