I'm kinda interested in getting a heavy bag. Primarily just for cardio use. I'm not looking to get in the ring or anything. But the place in my garage I want to put it precludes me from hanging it. I've seen things like the century wavemaster that has a heavy fillable base. If I put in on a rubber mat I'm wondering how much it might move around. I've also seen stands that can hold a hanging bag, but they look pretty large and bulky. Anybody using a bag that's not hanging from ceiling? What are y'all using, and what are your thoughts?