I give you a few important tips; You need to use a tripod and you need to work at mm precision. :)
The first few times I did a measurment with Audyssey I thought; I understand the benefit, but I also hear the limitations. So I started to do it differently.
Other people can try it out as well. You are not a mongol, are ya?
The new surround Onkyo receivers are in stereo a lot better than the ones of last year. They also will give stage depth.
In the tests I did between the old and new Onkyo receivers. I only found out that in Multi channel with Audyssey the stage is deeper an wider. And you hear also more decay. They use better capacitors, these give a much more musical sound. The individual focus of instuments and voices with the new ones is also a lot better.
For me personally without Audyssey Pro I never can create the level I have. I will use the 5509 longer. I also will go on for some time with the Integra 80.3.