I've Westone 4R's and I absolutely love them.
I'm planning to buy the X5 for portable setup. I've been listening from my Xperia T smartphone and I heard that the difference is huge with a high quality DAP.
Fiio X5 seems to be a very good choice but I want to make sure that they are a good pairing or not with Westone 4R's.
If someone experienced this setup than I'll be very thankful to hear some comments.