My wife is using hitting the tennis ball as I write this review. I have to say, we were both really skeptical that it would work because the base doesn't seem like it would be heavy enough. It was a bit annoying to fill up with water (it would help if the filling hole was a bit larger), but once you have it filled it barely moves at all. My wife (she played tennis throughout school) said it is a good way to really work on developing a technical swing because in order for the ball to return back to her. However, you can't just hit the ball anywhere otherwise it will return back from all sorts of angles. You still need quite a large, flat space to hit on, but it sure is a lot smaller than a tennis court (and you can play by yourself). A regular sized driveway should be plenty of space. Overall, we are really pleased with this!