I've had an A818 for over a year now, and while it's a fantastic device and still works fine there just isn't enough space, and since there are lots of offers for 16GB players I figured i'd start looking at upgrading. However there are now a bunch of models that are all ever so slightly different that it's hard to tell what exactly is different about them. From what I gather... -A series has bluetooth/wireless headphones, but no radio and relatively lower battery life -E series has a longer battery life (46 hours or something?) and it has a radio, but it's made of plastic -S series has a decent battery life (40-ish) and also has a radio, and it's made of aluminium Not sure if they're entirely true, but any info shedding some light on this would be greatly appreciated.