I've been using my fiio rc se1 for about a month now to my shure se535 (clear). I bought it because my stock cable is already oxidizing and it makes me sad everytime i see its poor state.
With or without sound improvement was actually ok with me as long as i see my se535 sexy again, besides I really dont think that there would be any difference in the sound quality. I dont believe about improvement in sound quality just by simply changing its cable -- until -- my own ears heard it.
The bass are now tighter and has more impact, the soundstage a bit wider, highs are clearer and the overall sound became a bit more crisp and detailed.
In contrary, I would say that these improvements did not "wow" me, i mean, yea it sounds better than before but its really not that much of a difference but dont get me wrong I am happy with the sound improvement especially the bass. And besides with a price of only Php1,400 (do the math) i think it is worth it.
Keep in mind three things about this cable though:
1. I think the connection is somewhat a bit loose that at some point, my music gets on-off especially if i turn my head abruptly or if purposely wiggle the cable.
2. The 2 inch-plasticky-memory-thingy is sometimes not comfortable when its edge touches the back of my ear.
3. When my music is off there is the microphonics that is amazingly annoying.
Like: A new cool look to my Shure se535 and a bit overall sound improvement.
Dislike: As mentioned above :P