M218A+ and M218B, as new edition of M218A, have already been put into the markets. they have a lot of improvement compared to M218A which is a perfect PDF reader. for instance, Wifi,P2P,flash and so on.
If you can read in CHINESE, YOU can see:
A and A+
http://www.baizhan.com.cn/index.php?showforum=824
M218B
http://www.baizhan.com.cn/index.php?showtopic=66021
http://www.jcnip.com