Pros: Build quality and sound are fantastic
Cons: didn't come with a tip that fit perfectly
I'm not sure where to start with these. My last pair of IEM's were the Vsonic GR06's and they were some fantastic $60 IEM's but unfortunately one of the driver housings cracked in half due to my brother leaving them dangling from a car door when he went on a trip and despite my best efforts to weld the plastic back together; it didn't stay together without falling apart. I decided to buy another pair of IEM's in the same price range but this time I wasn't about to settle for some plastic-housed headphones. I didn't see any reviews for the HA-FXD80's except from a particular head-fier everyone knows. The HA-FXD80's met my criteria so I found myself ordering them on eBay from Japan (only place that seems to have them) for $73.50.
Isolation: it could be better but It's probably due to the fact that they only came with 3 tips that wasn't a good fit.
Comfort: I have pretty tiny ear canals so I sized down to the smaller tips and they weren't uncomfortable but they could be just slightly smaller to be perfect.
Accessories: 3 Silicone tips, cable clip, cable winder, velveteen carrying pouch
Microphonics: The thin cable makes them inaudible when you're moving around especially when worn over the ear, which I never do.
Sound quality: Alright since I have a limited experience with headphones in general; I'll try to sum up the sound quality the best I can. They are the first carbon nanotube IEM's I've ever seen or heard and they honestly sound fantastic. I'm not the person who goes after bass but the bass on these are so deep and powerful in the low end. I can't believe how much sound the tiny drivers can produce. I burned them in for around ~40 hours but right out the box, they had a lows that blew the GR06's out of the water which have had well over 100 hours of use. I was impressed with my friend's Head Direct RE0's and I think these sound incredibly similar, with slightly more low-end bass and slightly recessed high-end treble. Out of the box, the treble is a little too much for me but continued use made them just right.