Aside from those 15 weeks (only 10% of my training since august 2007) I have been focused on strength. All my core, structural lifts (bench, squat and all its variations, deadlift, and all back movements) had been 4-6 sets of 6 or less repetitions... needless to say my periodization graph would look more like a horizontal line at a high intensity with a couple of twitches in it.
I am not a fan of lifting for high reps, but I should be... at least for a couple months a year. I love the shock undulating periodization gives to your body. If some skinhead looking guy approached me with this past programming, I would smack him in his fat head and tell him that you (and more importantly your joints) need some type of break from going heavy on every lift ALL THE TIME.
Now I'm sure there are some nay-sayers out there that never, EVER go for higher reps. I can only assume that they have their fair share of injuries as well. I am not talking about one set of 25 reps per exercise... that would be moving you into an endurance program for some one that could care less about any real type of results. I do not mean 5 sets of 20 reps--- you might as well shoot yourself. I am talking about 3-5 sets of 10-12 repetitions, with a drop set once a week per muscle group.
I am on week three of my high rep month and hitting every exercise as hard as I can, knowing that my master plan is playing itself out. I want to be strong... like, what is he taking strong, you know? I don't want to be a powerlifter whose stomach combos as a table/shelf when he sits down. I also don't have any attention of getting super lean (sub 6% body fat). Don't get me wrong, being a giant powerlifter means you work hard, being a body builder that gets to 4% body fat menas you work hard. I want to be around 11% body fat and still be pushing 315 on flat bench for reps.
I am going to do one more week of this high rep scheme and then go to sets of 8's, then 6's, then 5's, at 4-6 weeks at each interval. I will let you kow how it goes. What does your current program look like? Let me know in the comments.