Since you already have the T68, why not just watch some video reviews of the Poke 3 in action to see how it compares?
I would suggest My Deep Guide on YouTube for in-depth reviews of various ereaders, including the Poke 3:
https://www.youtube.com/watch?v=kHA3X5CYsbQ
However, there are plenty of other video reviews out there which will give you an idea of how the Poke 3 performs under various circumstances. You can then compare that to your experience with the T68.