Hi,
I wouldn't advise it for three main reasons. The first is that your body needs variety when working out. You need to keep it guessing. I love circuits too but mix them up and alternate with other forms of cardio. Secondly, you are right, this is not really a strength training workout, there is alot of anerobic and aerobic cardio segments and you won't be able to workout the muscles you do workout as well as if you focused on weight training alone. Also, there are only a few weight training exercises on this workout and you need to have a weight training program with more depth and variety and so you want to add days when you primarily focus on weights. Third, since this workout has several anaerobic intervals, you don't want to do this all of the time as you need to balance your cardio with steady state cardio. Variety is not only the spice of life but it makes for a more rounded fitness program and one in which you are most likely to make fitness gains.