I agree. Also the section on evaluating your strengths and weaknesses, and setting training objectives to address them (in addition to cycling goals) is very useful. I should work through that again for next season.
I use a modified version of his training plan spreadsheet to plan my season. Some people plan every workout. I don't like that level of detail because I'll stress over missing workouts, so I plan in general terms what I should to each week for the season, based on my 'A' races.
The most valuable thing I get out of training with a power meter is tracking my training load. I use GoldenCheetah, which is open source and runs on Macs, Linux and that other operating system. It will work using TRIMP to track training stress if you don't have a power meter. TRIMP uses perceived exertion to rate rides. You can use GC without a PM. I wrote the original GC Performance Monitor that tracks training stress back when I had time to contribute to it. So if it sucks you can blame me.