Let me clarify then...
1. No security system is fullproof, someone, someway will always find a way.
2. So what you have to do, is pick a method/system that gives you best security with best performance.
I do not claim to be an expert, but i use mac filtering, is because encryption adds to the cpu processing...And mac filtering does not, or not as much so...
And for me performance is far more important than high level security....
To be honest, if there was a way, i'd even disable wireless, as I really don't need that functionality....