Yep, I had both an XO and an EEE in that order. The look on the university help desk tech's face when I brought the XO (running puppy Linux at the time) in to get a network cert install was fun. I recall moving from the XO to the EEE mainly because the latter was faster and more pleasant to type on. There were few other competing net books at the time.

Then "direct descendants" is just a poor choice of words for describing an entirely different relationship.