It is ok, for the basic drills, like practicing the strokes, that's what the price would offer to you. But I won't bother to use it for footwork drill. I have tried a few times, but the inconsistent ball shot speed and frequency cause some trouble. And especially you dont know where is the center line of the robot.
But overall, if you want to save some money, just do a simple practicing, this robot still give you what you need.
I would suggest the Newgy 540 over the Ipong. They're fairly at the same price although they have sales for the Newgy. Plus I believe it's upgradeable if you ever want to get the net system or what not.