Buy it, buy it, buy it!
CTX was my first foray into the wonderful world of Cathe and it was one of the best purchases I've ever made! The discs themselves are chaptered semi-minimally compared to the awesome standards she now sets for the rest of the field, but don't let that fool you. CTX is such a versatile series and it is chaptered well enough to break them up and mix and match them with other workouts. I use bits of CTX in every rotation I do. It has 4 great ab routines (2 with planks, 2 without), FABULOUS music, and a great mix of hi/lo, kickboxing, step, and weight work. There is such a variety packed into those 6 workouts. The first disc contains Step Intervals, All Step, Power Circuit and 10-10-10. The 2nd disc contains Leaner Legs, Kickbox, all 4 ab segments, and all 5 upper body segments. I can't recommend this series enough!