It all depends on what you're using the device for.
If it's just reading then you can go with any device.
If you want to edit documents and write on the text then i would suggest the jetBook Color - plus it has a color e ink screen which is pretty killer.
They're supposed to come out with an update for this month that a lot of us are waiting for - my thoughts it will have the WiFi feature activated for sure and prob some other cool stuff.
You can check out the original thread about it here:
https://www.mobileread.com/forums/sho...=jetbook+color