I've bought the YBF with the gray cable on DD-Audio store some weeks ago just for curiosity's sake and I got it yesterday. My pair was inside the carry case, which in my case is just a plain carry case instead of one embossed with the UF monkey.
Fit-wise and QC-wise, no issues at all. I like that you can wear them cable-down swapping sides and wearing a straight MMCX cable without ear hooks, judging by pictures I thought the shell would be bigger, it's a tiny IEM and rather comfortable to me. As far as my poor man's measurement rig goes, they have a perfect channel matching (and the curve is very similar to the one crinacle measured). No MMCX issues so far regarding the sound losing the signal or loose socket.
My initial impressions are positive, the Urbanfun has hefty lows and just a bit too much for my taste. When the music has strong sub-bass they definitely won't be shy and give a nice massage to your ears. It's a cool effect for electronic music that I listen to
(e.g. Jon Hopkins, Rival Consoles, Fakear, deadmau5, Ruby My Dear, Trentemøller etc...) but after some hours of playtime, it can be a bit tiring but I've found a good solution without EQ
*.
Also, it's a good match for metal, drums sound fast and punch, might vocals won't be as smooth as the blons since the overall timbre is more sharpened on the YBF so it can give a bit less "emotional" presentation and more energetic version of the music. I can see people who are into some calm genre preferring the Blon over YBF. It works excellent with something more lax like Leprous, Soen, TesseracT or harsher like the Igorrr -
Parpaing or Illdisposed -
I believe In Me. Since I listen to 80% prog-metal and 20% electronic I gotta say I'm happy with the purchase.
I'm still in the process of tip-rolling and evaluating the sound, so might my impressions change after some time, for now, I settled with Sony Hybrids and liking the Radioshack (Auvio) tips, but I like a bit darker presentation then the Sony works better in this case.
* My solution for less bass is just covering the top-vent with blu-tack. I do prefer a bit less elevation in this area and that works well for my personal taste, YMMV.
Here's the graphs showing the effect:
It's not a drastic change, but enough to be less tiring and better controlled for me.