I personally think this is a very clever idea and an excellent option for apartment dwellers. My brother has done something similar for his dogs. He has three Pekingese and the dogs are unable to go up and down the stairs from the porch to the yard. He can carry two down to the yard and by the time he gets back to the third it has relieved itself. So he made an area on the porch (which is a completely enclosed screen porch) layered with newspapers and a large heavy bucket in the middle for them to lift their leg on. It isn't pretty but it's functional.
Many Basenjis are trained to use litter boxes though this is not neccesarily a good option for a male who lifts his leg. Remember though that while the pooch potty is great for quick potty breaks, you will still have to walk the dog for exercise. And I agree with Rivermoon that the dog needs to be supervised while on the balcony unless it is enclosed. There are too many tales of dogs who took flying leaps off balconies to consider unsupervised time on one IMO.
Let us know if you try this product out. I am interested to hear how it worked.