I've found that CAA has always been quite helpful, from the security guard to the FCL staff normally, when I had dealings with CAA.
The only complaints from me were bureaucracy, the 'telephone queue and that awful repetitive music' and sometimes not knowing what's going on (but that's not the staff's fault, but the legislation not being clearly in place, I guess)... but as I said, the people in general have been helpful, or at least tried to help.