GGL line has even sorted out somewhat unusual requests from me also, taking trouble to find out what they are (not something widely known), and getting them done. When there were some issues that arose through errors etc, they have sorted them out promptly, courteously and efficiently also. I haven't come across a poor agent yet, although I suspect there would always be one or two as with any organisation/department.
A very happy customer here. Saying that, I have only been a GGL for the last two months, and I don't think I'm the most demanding customer they tend to come across - if anything I'm normally quite blasé (except about some bizarre little things at times).