As I prepared to leave for college, I worried that my martial arts training would suffer, so I took along my Power Target Pro. It's small enough to fit in my dorm room and quiet enough that the neighbors never complain. A few friends beat on it, and liked it so much that we're pushing to have one installed in our campus gym.
The PTP has helped me both in the classroom and with my training. I never needed anyone to work out with me and it can stand up to any hit I can deliver - no matter what direction or strength. Definitely the most useful martial arts training product I've ever tried.