I would describe C/S as average overall. The call center people are normally pretty decent and willing to help.
What is amazing to me is how bad many of the agents are that work at the airports, especially those that get to work the special services desks. If you don't tell them what they should do for you including connections, they are at a loss. This may be due to lack of training on the (new?) system but they always struggle when it goes beyond the simplest things.
My standard route these days (about every other week) if PHF-PHL-LGW and back. At PHF, they frequently struggle checking me in because they don't know the int'l country codes when entering passport information (I travel with something as exotic as a German passport).
My most horrific experience was last week the day after all the snow issues up north.
I was re-routed on BA from PHL-LHR since the flight from PHL was running 2 hours late but when I got to the gate in PHL to get my boarding pass for the BA flight, I was told by BA that whatever they had done for me at US check in was wrong and I had to find somebody at US who could re-issue my re-route ticket to include all needed comments for the re-route. Long story short, I spent the night in PHL (still waiting for an answer on reimbursement on that ) since the places I was sent to by US agents and the incompenet ladies at the US Airways Club were closed and then I had to walk to Terminal B for the only open check in counters at which time the BA flight had long taken off.
I always have the impression that they try but the level of skill is sub-par.
Maybe it is simply impossible to attract good people to an instable industry such as the airline sector.