Hi John thanks for posting,
Here is a even better video by John Cooper.
http://youtu.be/X3_7jYIif2QUnder comments he says. "He Replaces A lot of the Stock Balsa With Contest Balsa Wood"
I used to use the stock kit wood. However, I feel there are too many variables in stock wood. There are weight issues, strength issues and the sheets differ greatly in quality from each other. Also I'm starting to get better at what's called "Grain Pattern". Which is cutting out the part with or against the grain to make them their strongest. Now don't get me wrong. I don't want Guillow's to use better wood or to go to Laser Cutting. I actually commend Guillow's for the great job they do. In the past I have built the kits with stock wood and they flew. They don't fly very far but they did fly is what is important to know.
I as a kid/teenager I built/flew Guillow's kits. We didn't have "Gaming" and we liked it like that. Unfortunately there was no known flying groups in my area growing up. I had to relay a lot on my father to show me how to build. My father did not know very much about flying models though. As a teenager I did buy the book written by Don Ross. He even autographed my book for me before they sent it to me. Anyway although I used kit wood and kit rubber motors I did have some success with the Lancer and Arrow kits.
Anyway here is a site that calculates wood weights.
http://www.nclra.org/Programs/BalsaDensity.phpBTW I use 5 lbs graded Contest Balsa Wood. on all my parts. Since I post builds I really should add weights to the build. As far as cutting out the parts goes there really are not that many parts to cut out per kit. The benefits of using Contest Balsa Wood definitely makes it worth the extra effort.