This is just personal anecdote, so take it FWIW.
I tried using the “Hypertrophy” programs in Cosgrove and Schuler’s “New Rules of Lifting”, which used a form of periodization where you’d go 5x5 one session, 4x10 the next, and 3x12-15 the next, and didn’t see much improvement in leg hypertrophy at all. Now, I’m using Rippetoe’s 5x5 (or 3x5) program, which calls for squatting heavy three times per week and the progress in the leg department has been much better. I guess I don’t see the point using a periodized program when squatting heavy often seems (anecdotally) to be better and simpler.
Also, at the same time I’ve been using Rippetoe’s program, I’ve been doing fat loss and the results have still been good. My strength has gone way up and I’m now squatting and deadlifting over 300, which is not impressive but progress for me. The strength gains came rapidly on his program.
Aside from that, Rippetoe’s book is written better and is better organized without too many annoying attempts to be clever or funny.
Thoughts?