Jamie,
As a Crestron programmer I strongly recommend that you look for individual top shelf components to handle the duties that they were designed for. For example, I have used Lutron Homeworks, Spacer System, Radio RA, as well as Vantage products which all can control lighting, then Crestron to interact with them.
With Vantage, their keypads were put in place throughout the home to give a similar style to all keypads, and then Vantage and Crestron communicated with each other to give the final result of whole house audio. Seamless blending is the key and a good custom installer can make it all work flawlessly.
As for using 'Crestron' for everything, it is not something that I typically recommend as I do believe that there are either better, or cheaper/similar solutions from many other companies out there which will give you more bang for your buck. BUT: Actually being able to use things is CRITICAL to a nice system, especially with whole house audio and video. So, I would not typically put a panel on the wall next to a keypad, but would have keypads control things everywhere, then enhance their operation with panels in key locations.
I am not at all aware of EIB... go figure. I also am not aware of what issues you have heard with Crestron. In my experience Crestron is one of the few highly proactive customer service companies in the world. Top shelf stuff and when a product is defective, you are typically covered under a 3 or 4 year warranty and in the first 90 days or so they will advance replace most items that need to be fixed. That is a sign of a company that actually cares. Of course, there is a price tag involved.
Jandy pool/spa controls, multiple choices for lighting, HVAC? multiple choices!, security? multiple choices! The bottom line is that a repuatable dealer will definitely be able to help you get the best of everything for your dollar (pound/euro?) and will work out the initial bugs so you have a stable long term system.
