Won't buy on the basis of these specifications. Might buy the next, even-numbered iteration (I passed also on version 3).

Concerning the infamous rear speaker, I had a nice improvement by installing and fiddling with Viper4Android Fx which you can find in http://vipersaudio.com/swupdate/vipe.../download.html .
You need root.

Sound is much more convincing enabling just a little bit reverberation, speaker optimization and extra-loud even with the crappy internal loudspeaker.