I am a low rep guy. I train in the 1-5 rep range for most of my big movements. To counter this, I do my metcon work (when I do it) with kettlebells, the jump rope, the heavy bag, and bodyweight calisthenics (because that's what I can do in the basement when the back yard is mush).
When I first looked at the workouts in Afterburn, I kind of snickered. Just take the first one:
Each couplet is a superset.
Squats: 20 reps, 60s rest.
T-Push Ups: 8 reps each side, 60s rest, then repeat 2-3 times
Step Ups: 20 reps each leg, 60 sec rest
Rows to neck, 20 reps, 60 sec rest, repeat 2-3 times
SHELC: 20 reps, 60s rest
Ball crunch: 20 reps, 60s rest, repeat 2-3 times
Doesn't look all that hard.
It floored me. It was so far away from what I normally did with weights that the minimal amount of anerobic conditioning that I did perform didn't help me much.
So, basically it's all about managing EPOC, and eating right, and performing both appropriately metabolically challenging weight work with interval energy systems work.
(EPOC = excess post-exercise oxygen consumption)
It's was, for me, a big surprise when I finally bit the bullet to try it for real.
If you're a dedicated XF kind of guy, to be honest, I don't know if it's going to be as good for you as it is for me.