Crestron is a great company with great products and even very good technical support. But over the last 5 years (or so), I've noticed that Crestron has been a company that is more reactionary than visionary.
Example: Adagio was released as a product line to placate the many dealers who were complaining to Crestron that they were losing bids due to their high price and complex (and expensive) programming- even before the recession. At the time, Crestron was aware of Control 4 but I don't think Adagio was necessarily released to compete specifically with Control 4. Prodigy, however, is COMPLETELY a reactionary product to Control 4. If anything, they are giving Control 4 a ton of credibility in the market by releasing Prodigy to compete with them. It's amazing to me that a company like Crestron that has been around as long as they have now find themselves playing catch-up.
Control 4, on the other hand, continues to innovate and more importantly position its products by addressing things people really need, such as energy management and conservation (among many others)- and are doing so at a very fair price and simple integration. They seem to be very tuned in to what dealers need to stay competitive across the board.
So while I believe both companies are good and each have their strengths, it's Control 4 that seems to be focusing on the future, where Crestron has relied way too long on their name and nothing else and now find themselves in a hole that will be very tough to dig out of (at least in the residential market).