It's a shame I went ahead and ordered before I looked into all the alternatives. I didn't know about Naeb. Oh well, so long as I get my Cybook soon I suppose it's okay.
It's just a shame I paid an extra hundred bucks I didn't need to, just for an extra battery.

I was half tempted to cancel my order through bookeen and switch to Naeb... but I used a debit card not a credit card and I don't know how well cancelling would work. At this point I'm not sure it's worth the extra hassle to save the money.
I suppose I know for the future, though.