Hey There!! I started doing BodyPump classes about 4 years ago (2 per week) and though I was fit and toned I found that after about 4 weeks I was definitely stronger and getting more chiseled all over. I gained some nice new cuts in my forearms, biceps, shoulders and upper back and my legs had more definition and again were definitely stronger. The biggest change was in my glutes which like to be flat and started to round out at the top. Mind you I hadn't worked with barbells before and was about 6 months from discovering Cathe.
I now teach BodyPump twice a week and yes, it is more endurance based but when I am putting together my classes I throw in at least 2 tracks that work with slower counts and more static holds to encourage strength gains. I guess it depends on the instructor, I like to lift as heavy as is possible while holding good form and get tons of feedback from my members that they feel the difference between my classes and other instructor's classes (I LOVE that }( !!)I'd say try at least a half dozen classes and see how that feels (and looks). I love this programme and would encourage anyone to try it. If you can do Cathe's weight workouts with good form then you are definitely up for it. Let us know if you try one and what you think