First off, thanks for writing such a great guide (and creating the xbee adapter)! It was very helpful.
Unfortunately, I ran into pretty major reliability issues. I was able to transfer the Blink sketch (~900 bytes), but had trouble with anything much larger. The biggest sketch I successfully uploaded was 4k and that only worked about 1/5 of the time (with the two xbee modules a couple inches apart).
So I started playing with the XBee settings to see if I could improve matters any. I had little success until I switched the "IC - DIO Change Detect" setting from FF to 08 (the guide says to use FF but that technically 08 would work). Surprisingly, this made a huge difference. In fact, it completely fixed my reliability issues. Now I can consistently send a 30k sketch to the remote arduino (when it's two inches away, anyway
).You might want to consider updating the guide to suggest setting "IC -DIO Change Detect" to 08. It made a huge difference for me.