About poor battery life: Don't keep on the wi-fi connection all the time. Every e-readers decrease its battery very fast if you do it.
About the other problems you mention, we know them very well and are not yet fully recovered. Actually there are other ones, such as poor dictionary and highlighting functionality for example.
I have to say that there are some M90 devices without blind spot. I have one of these devices.
I suggest you to upgrade the firmware. The latest one you can find here
http://www.onyx-boox.com/onyx-boox-f...x-m90-firmware
You can update the software by follow steps:
l Download the latest updates package from Onyx website:
www.onyx-international.com
l Save the updates package in a SD card.
l Make sure the updates package is located at the root directory of the SD card. The name should be 'onyx_update.upd'.
l Insert the SD card into Boox.
l Restart Boox, press and hold the OK button. NOTE, the OK button should be pressed before the device restarts. Hold it until you see the message 'Software update request detected, checking updates…'.
l Boox updates itself automatically. It restarts after update finishes.
Reminder: Make sure Boox has enough power to finish the software update (at least 2 grids displayed)