I'm a Gym owner and have been for over 30 years and I personally own and love the Assault Bike! If you looking for a great workout in a short period of time this is great piece of equipment. It's light weight, has a small footprint so it can fit almost anywhere and easily moved from room to room if need be. The 12 round mentioned here is an excellent advanced workout for those in good to great shape but can be modified to work for the beginner to intermediate workout enthusiast. Anybody interested in a complimentary mini-membership to any Crunch in San Diego let me know please. John