I've done it twice now as a Mesocycle, and often will use one of the Meso 3 dvds as my Legs workout in other rotations - it's my favorite way to push Leg strength.
What I do is increase weights until I can just barely complete each set in good form, so that the last rep takes all my focus. That normally means I'm increasing the predicted weights from the workout manager (yes, I had to buy new plates, and even a new barbell this year because my old one only went to 140 and was beginning to bend!)
Mesocycle 3 (for me anyway) doesn't burn anywhere near as many calories as either meso 1 or meso 2 legs while you're doing it. This is not a cardio workout, and even though my heart rate spikes pretty high during the set, much of the workout is the muscle rest period, and so the overall calories burned are usually about 1/2 to 1/3 for me as compared to Meso 1. However, on the plus side, this Meso really will help your strength and I always end up more than ten percent stronger when I finish it. I also think it gives my metabolism a big boost, which leads to more calorie burn after the workout! When I push myself to the fullest on Meso 3, it really does take the full week before I recover enough to go heavy on Legs again, and requires good nutrition/sleep too.
If you don't have enough plates to meet your goals on the workout manager, then it may make sense to go with the Plyo legs instead, or else substitute the Legs from Meso 2, or add a few reps. All depends on your goal.
