I too have the AMS 800 and it has worked fine for me from the beginning. There are many others on the forum with the AUS as well so you should hear from more. I have not heard from anyone who was leaking from the start. You can expect a little residual after urinating if you don't give the cuff time to close. Other than that you will find most of us have very little if any leakage. I wear a light ladies panty liner to catch residual leaking (I don't have the patience to wait 20 seconds or so after urinating). A little trick I learned on the forum is to press on the urethea below the scrotum to squeeze out some residual after urinating which helps with the residual leakage. Also, I can accidently activate the AUS if I sit wrong and that will cause leakage as you would expect.
I have written a lot on past threads and the links to them are in my profile below.
If you continue to leak as much as you indicate I suggest you consult with your surgeon. It sounds like the cuff is not closing properly.