I have one small suggestion for a future revision and that would be to add an out line or some kind of marker in the silkscreen to remind the user which way the XBee module gets plugged in. I notice you had that on your prototypes, but it's been removed from v1.3.
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16