I have used Slim in 6. While it's a good workout (my leg and butt muscles were ON FIRE during the excruciating floor routine--holy crap!
), I found that after a few weeks I got sooooo bored with the repetitiveness, and it was very difficult to find the time and motivation to workout over an hour a day for six days a week. I am not a morning person (I tried), and in the evenings by the time I got home from work, cook dinner, do household chores, help my child with homework, laundry, etc....it's 9 or 10 pm and I'm pooped out! I stuck it out for the whole six weeks though. I did not lose much weight, but I *did* lose quite a few inches all around. If you can stand doing the same workout six days a week, it may work for you but you have to really stick to it. Don't let them fool you into thinking you're going to have this huge difference after 6 weeks either. That may be so if you don't have much to lose but if you have alot of weight to lose, you're going to have to do this workout for the better part of a year at least in my opinion.