My personal experience with Chinese batteries and battery packs, is that the milliamp hours figures printed on the sides are always heftily inflated.
It wouldn't surprise me to find out that the 'new' 2000mAh packs in the new X3s are identical to the 'old' 1500mAh packs. It seems as if the law in China, about such claims, is quite different from what I'm used to in the UK.
Having said that, Duracell 2300mAh batteries are well short of that, in my reality.
There is something of the "No 11" ( as in the movie Spinal Tap ) about rechargable battery manufacturing claims.
I'm not using my X3 much, as a portable. The battery life is not sufficient to inspire descision making confidence when preparing to leave the house. What I do use it for, more and more, is as a way to get DSD files playing through my non-pro studio monitoring setup. It's a great sounding setup and I can really get a good feel for how well a particular source is delivering, and, of course, how well the media is sounding. I use a Sony D100 portable recorder, which can record in DSF format. I can convert those files to DFF format using Korg's Audiogate software. Not ideal, but it gets me there. I'm slightly infatuated with DSD audio, it's got something special about it, to my ears. The big downer, though, is that DSD editing software is rediculously expensive, I mean thousands!, and there's not even a lot of it about, even if I were an Oil Prince.
As a source, the X3 is not "Great", I've got better sounding analog sources. It's pretty damn good, though, and certainly good enough to get on with some proper grownup audio work, using digital files. The simplistic interface, in XDuoo's own OS, is ideal for handling just a few high quality files. I've not yet actually done a check, but the DSD mode seems to be running at the right speed, to my ears.
I have Rockbox installed, as an option, too. I'm curious to know how many different formats of sound 'modules' Rockbox can play. I have thousands of them, and a short list of favourites. They are in several different formats, MOD, S3M, XM etc.
I'm an old geezer-ish, and have come to digital audio after a very long run with older analog technology. I record a lot of stuff. Nature recording out in the woods, my own attempts at making music and more recently, recording samples of my own 'musical' sounds for working up into complex mixes on the computer using a great old program called nTrack Studio v3.
Last year, I experimented making several different flavors of Psybient music mixes. This year, I'm going right back to my own basics and making fresh original material to work with [
I think I can feel an Album, coming on 
]
I like the quirky ways of working on stuff. Filling a folder on an X3 and plugging it into a processing chain of analog gear and recording the results, is my delight, and keeps me away from the dreaded DAW ( Digital Audio Workstation ) grindstone and mind masher.
I little off topic, maybe, but that's a glimps into my X3 world, as it is right now.
