It's nice to see the series continue; previous tutorials in the series are listed on AE Portal.
By the way, Chris & Trish Meyer have a similar series behind the wall at Lynda.com, except it ran though filters by Effect category (as in the Effect Menu). Chad Perkins also had a similar treatment in his Lynda.com 2008 series After Effects CS3 Effects.
Update: Crish Design noted on Facebook, "What the Blend effect is even better for is when the footage does not fill the frame - in other words, crossfading between two layers with unusual alphas without having an opacity dip in the middle of the crossfade. ..." And later John added some clarification to the original post.