I absolutely love contrast training - it is my favourite way to train the lower body. I personally do it no more than once per week and then after 4-6 weeks I switch to another style of lower body training (heavy weights, barre, mat, pyramid, etc.). The Cardio Legs routine in XTrain is also a great contrast training program.
The benefits I see are increased cardiovascular fitness while at the same time lifting fairly heavy. So lots of calorie burn without losing muscle mass. I just did STS Disk 26 last night - whoa! Super tough! The heart is pounding (hiit type benefits), the pylo moves help me build bone density (I have low bone mass so I love that benefit), it is time efficient (Cathe just gives about 30 seconds rest between rounds), there is so much variety within the workout there is no boredom (only one set of each move) and I feel as if I am working toward stronger yet leaner lower body musculature.
Great idea to do the squat rack option while doing Meso 3 and then the Plyo option the following month.
Good luck Debinmi!