Re: wanting to compare 2 books
You are comparing apples and oranges.
Shioda's book has more techniques.
You can't learn Aikido from a book.
If you study Shioda's style (or a related one) of Aikido then it may be helpful as a reference to supplement your teacher, but you can't learn Aikido from a book....
Shifflet is especially valuable if you are a beginner in Shin Shin Toistsu Aikido or any of the offshoots. Seidokan, Kokikai, Shin Budo Kai, etc.
I usually only recommend Aikido books that cover philosophy, history or 'verbal aikido'.
If you are insistent on a technique book buy a DVD instead.