i think that they used dual PMP for the video side of things as android can be a picky git with video playback and this was there way of just loading a basic set of functions to better utilise the hardware for video as this is what they know best and have spent their time developing .. its always been about video playback now for several years - apart from that and for the rest of the use Android would provide a better system
as with Chinese production many companies using same hardware reference designs, so the dual boots are all novotek based ref design and teclast, window et all just take that and shove it into their own case design and pick ancillary components to make a player with it .. same with the rockchip based ones etc etc
rockchips budget chip for android is the 2816 .. but this suffers from lower power, only supports lower grade ram and can be a little slow although for the nationite rocktab KRISTO did get 2.1 and 2.2 running on it but a little slow and clunky
the 2828 based rockchips have better memory access for RAM using faster DDR? ram .. 256mb is a starter value and can cause problems for android hefty requirement sat times
there are loads of android development forums around but i dont think many or any have taken to heart the smaller wifi-less models so i dont know if any work is being done elsewhere on these android pmp players
window are a nice brand, teclast can be hit and miss as can onda, ainol are pretty big but lack commitment to their players (well .. as do 90% of these domestic chinese companies .. they churn out players like no tomorrow)
some random chinese reviews of the wifi-less players(u will need google translate)
http://www.imp3.net/1/show.php?itemid=31388
http://www.imp3.net/1/show.php?itemid=31427
http://audio.pconline.com.cn/mp4/gui...5/2416814.html
of course having no wifi means manually installing apps, which means trying to find the APK files to download and install .. but what they hay
just noticed that some of those cheap, <70 players have only 128 ram .. that could be a hindrance to the android OS as android like to multi-task by default, so task killers are the call of the day here