I do lower body twice per week and these are my go-to workouts. I actually "dread" Gym Styles much more because it's so tough. GSL does it all and has the best calf workout ever. Cathe even hits the front of the calf. I thought I wasn't really accomplishing anything with that when, lo and behold, I started seeing some front calf shape! On the other hand, B&G hits the sides of your butt cheeks - which I need and also haven't seen anywhere else. If you can get both and alternate them you can hit everything. But if you have to choose, get GSL because a more thorough lower body workout has never been made. You can always find exercises to hit the sides of your butt cheeks and tack them on. Still, I love doing both every week because I like variety and know I've hit EVERYTHING. I'm anxious to try Slow and Heavy, The Pyramids and, of course, can't wait for STS, though.