Funny to see this, the jack on my unit broke last week... For the past few months actually, I was hearing the hiss people complain about - which I found odd because I didn't have the hiss for a year. Last week all of a sudden I lost the right channel so when I opened it up I noticed the crappy glue Fiio uses to hold the jack down more securely had cracked; one solder point was loose and another broken right at the jack.
You should see my unit now, I epoxy'd the jack down so that it's resting on the solder points perfectly.
The copper ring also broke so I broke it off, bought me a splitter and epoxy'd THAT onto the front.
I figured, what the hell.. I'll do a cheap $5 job and try to fix it or end up buying another DAC that I can use at work.
If/when I ever buy a new E10K I'll be sure to open it right away and epoxy the jacks down so the weak points in the unit are rock solid.
The sense that I got from talking with FiiO and the little bit of info they were willing to disclose was that the E10k should be more durable and reliable. It remains to be seen whether there will be any DAC or amp changes. Expect it to be out later this year.