It is always funny reading the various biases that people state without first hand knowledge.
I can not comment on Russound but I do have a very large Control4 system. I am extremely happy with it. It works well, sounds great, the controls are good and can be use by everyone in my family, and the price was reasonable.
I also laugh that someone said that 40k was impossible. My system was more than twice that amount. I have lighting, whole house audio, data, security, hvac, home theater, shades, watering and more. Control4 has a great warranty and continues to expand their product line. Now I am only an end user and dont sell, install or market any of the various products. Though I have had a very good experience with Control4, I still believe that the single most important thing for you to consider is not the particular product but the installer that you hire.
All of these products (Control4, AMX, Elan, Russound, Crestron etc) are very very complex. A good sized system is composed of uinterrupeted power supplies, networks, several communication protocols (like wifi, ethernet, zigbee etc), many interdependent computers (everyone of my touchscreens is a linux computer), proprietary systems like security etc, etc etc. You get the picture. This stuff is complex. If a great paint job is partly dependent on the type of paint used and highly dependent on the painter and the amount of prep work done by that painter then a great home automation system is even more dependent on the installer. Pay a premium for a great installer who takes their time, designs the system well and will support what they do.
If you are interested, here is a link to post describing my system in more detail and other lessons that I learned.http://www.c4forums.com/viewtopic.php?id=965