Squash Game: Physics Dilemma

So far in my game I have been using Bullet Physics which is a free to use, open source physics engine. This was great for quite a while but I ran into some issues fairly early on. The next part of the functionality I wanted to implement was the ability to let the game know when the ball goes out of play. This can be done either by the ball bouncing twice or hitting the wall in a invalid position. To implement this needed some ability to test the collision of two certain objects and then call some sort of callback or trigger to do the game specific logic, which turned out to be more difficult than it first seemed in Bullet. I played around with it for quite a while, attempted to look at the documentation of which there is nearly none. I finally gave up and searched around on the forums and eventually asked a question myself to which there was no reply. Finally after wasting a lot of time I decided to look elsewhere, which is when i found nVidia's PhysX. I researched a little, making sure they had better documentation and ensuring that there was examples of the functionality I wanted to create, which there was. So now I am currently in the middle of switching to this new physics engine.  

Technically I am not switching the two I am just providing the functionality for the new Engine as all my code is wrapped up so that you can easily replace 3rd party libraries. It is still taking some time as I am having to learn this new API, although I have noticed that the Physics engine all tend to follow the same names such as "Actors" and "DynamicRigidBody". I will hopefully have a new demo up and running before you know it, I am still trying to juggle iOS development at the same time as this project and it is taking its toll on both projects. 

Keep it easy :)