Just got mine. It provides a really good work out, although it is kind of hard to get used to running without completely unextending the legs, and you can't jump for shots. But still I was tired really quickly. I strongly recommend this to you guys looking for something to improve footwork and knee bend and tennis related muscle stamina.
"I got dosed by you and
Closer than most to you and
What am I supposed to do, take it away ."
-Red Hot Chili Peppers, Dosed