I have it done

Yes, I habs done and bought me the Astell & Kern AK 100. And what should I say? He is really awesome! The sound is beyond doubt, worth no ifs and buts, that's real high end and worth every penny / Euro.
My model is the 2:40 and has not been reported from all the teething problems over here with the other reviews. Therefore, he is well worth a minimum of five stars.
I will also write any large Rezi, because the most important thing has already been said, only this:
It's all totally easy, box, attach and load the music. Just the pieces or albums draw from the hard drive down, is very simple and fast. You can also on the A & K create your own folders and the order by all kinds of things, such as genre, artist, albums, compilations etc.
The play on the player is just as simple, because everything is laid out similarly as on the iPod, including lyrics.
The cover transfers without exception.
German manual via PDFs from the Internet to download.
The only drawback: The player controls gapless Play still not perfect.
The iRiver program you need the way for new updates, everything else you can save in my opinion.
Everything else important was already described in the other Rezis, so I mean to bore anyone here.