I find all 3 to be endurance workouts (B&G, XTrain Legs, XTrain Cardio Leg Blast). They are all great and each offer something different and unique. I can't imagine how you could go wrong by enjoying all 3 of them in a rotation.
B&G uses a barbell and overall uses heavier weight loads than XTrain Legs. XTrain CLB can get on the heavier side with weights, but there aren't as many reps or pulses as there are in B&G.
B&G doesn't have any cardio, neither does XTrain Legs, but XTrain CLB alternates weights with cardio so you get the benefit of contrast training.
XTrain Legs is more of a toning workout, IMO, but that doesn't mean it's not challenging! You can go heavier than Cathe with your weights, if you like (she uses 5s or 8s, IIRC). XTrain Legs works muscles that I find often get overlooked in other workouts, and has lots of functional moves that are beneficial for someone with an athletic lifestyle.
No core work in XTrain Legs or CLB.
Random analysis, but in short, I don't think you'd lose your booty at all, especially if you included B&G and an XTrain Legs workout in your rotation each week. Just allow enough recovery time between workouts.