Well, I made the mistake to go to Fujiya Avic to check out the 846 again today. Still driven straight from iPhone 5, I got same impressions as the prototype I spent 45min with during the show. In particular, the 846 really does some magic, it's hard to put into words but for me, it is a very natural, foot tapping inducing experience...
I briefly tried the FitEar parterre, it had a similar tonal balance but somehow I didn't feel the same connection to the music.
I guess I'd need to sit down and listen for long while to make more quantitative comments on the sound but for now, all I can see is that the 846 simply sounds like music out of the iphone. If there's one word that comes to mind, it's cohesiveness: all the drivers are well integrated, you don't feel like you're listening to a multi driver unit. Also, I don't get sense of some frequencies being accentuated, it's very well controlled but still sufficiently detailed and resolved.
It's not perfect though. There's one thing bugging me in particular: the bass has terrific kick and extension but it's clearly 3-4dB too high in level for my tastes and definetely not what I would classify as neutral (driven from the iphone 5, a 3-4Ohm zout I recall?). The good news is that it doesn't step over the mid bass so it does not mask or turn into a one trick poney bass. That's where I realize there's only so much you can get out of the iphone's built-in amp.
In the end though, since I was tapping my foot the whole time and felt it has so much potential I actually went ahead and put my name down on the waiting list... I think the bass amount might get bothersome but I will try the bright filter or wait for the right dac/amp combo (I am soo waiting for a small guy with low z out, low gain / hiss and built in D/A that would accept lightning connector...).
Apparently there are over 40 people ahead of me on the list so I am guessing it's going to be a while till I receive them..........