I've never ordered from advancedworkouts but have read great reviews.
I've ordered from Collage and love their policy to send back DVDs even after you open and actually TRY the workout. I've done this with several DVDs and they credit my account within 10 business days. I always order from them when I have an "iffy" workout that I want to try.
Totalfitness DVD is wonderful!!! I've now place 3 or 4 orders from them and have nothing but high praise for the company. I always get my order super quick and they have free shipping for any order over $20...............that's 2 workouts!!! And so far, every order I've received has been shipped Priority not media with the free shipping. They have great service.
I don't think you'll lose with any of these 3 companies........go with the one with the best price, but if you are afraid you may not like a workout....definitely go with Collage.