The trouble with the Mini-M8 is that there hasnt been enough reviews or impressions as of yet.
One or two people have shared their impressions of the Mini-M8 and some have reported hiss, this is far from conclusive.
Usually the first impressions/reviews are what people remember - whether on not they are accurate or true for most of the users.
We havent enough information of what kind of source they were using, their files, the headphones etc.
When I tried it...