I was a little concerned my older cat would not use this contraption.  However, he quickly took to it.  I have 3 male cats who use the same box.  My second concern was that they would not share an enclosed space pan. They have and continue to use it together.  :)  
The reason I needed it was due to a new puppy who was eating out of the litter box.  With this in the bathroom corner it has alleviated that issue famously!  :)  Thank you for a great product.