I have used this thing at least every other day, 20 to 30 minutes each time, since the end of June 2012. I hit hard enough to move the 300 lb base all over the floor of my garage, and it's held up better than I thought it would. At first I was concerned with the looseness of the bag in the base, but I think this may be an engineered-in stress relief. No problems at all -highly recommended for exercise and getting rid of pent up energy.
Rating: [5 of 5 Stars!]