They work great. Excellent UI, easy searching of large library in our system, they come with earphone in the box, they are popular... however, the SQ puts off a lot of us. I do not hate it personally since they have one of the smoothest system and I can always use an external DAC but it will definitely cost more than just getting a pair of FiiO X3 or possibly X5.
It really depends on what you are looking for IMO
if you don't like the sound quality, then don't buy them ¯\_(ツ)_/¯
Personally, i went from 1st gen shuffle to 2nd gen shuffle to 2ng gen ipod touch, to iphone 4, to iphone 5. sound quality never really bothered me, bit i had crap earbuds/headphones at the time...
Not to say, i'm really happy with my X5.