PH, I love Westside for 6 very clear cut reasons:
Speed work
Strength work
Hypertrophy work
Planned rest
Active recovery
GPP
...ok 7 reasons,
RESULTS !!!
It is the most well rounded program I've ever seen. If you have the right body for it, and the right diet, you will get strong as hell AND grow like a weed at the same time.
The most similarly structured program I've seen is 5x5, which also turns out some VERY strong people with killer physiques.