I've only had the BF concierge help out once. It was more or less her keeping an eye on my reservation, seeing that I would miss an international BF connection from EWR-MPX. She was waiting for me just outside of the plane and had an electric cart waiting to take me to the PC.
It wasn't really all that necessary, but it was a nice gesture. She was re-assuring (and ended up sending me through FRA to MPX).
The silver lining in all of that was CO's mileage promo from EWR-FRA, snagging me another 3K miles on top of the bonus. Always good
BN