My experiences:
Business Travel Service:
-- They arranged various hotel stays for me. Most of the time, a better rate on the internet could have been found. Anyway, everyting that was not about the rate, was great: Always they did not just do a stupid computer booking, in each case they sent a fax to the hotel directly, asking for upgrades, late check-outs, etc. Also, sometimes they called me about ten times without showing any annoyance even about two-day-stays at non-chain hotels in small towns in Italy. For sure, there was not a big commission to be earned for them ...
-- Car Rental: hopeless. As a Sixt Platinum, you cannot get better rates or upgrade in Germany trough Amex.
Holiday Travel Service:
After I returned from an AMEX organized holiday over christmas (they booked a sheraton for me via a tour operator) I received a personalized and personally signed letter after the holiday asking me how it was ... nice!
Life Style Service:
-- Ticket bookings: Simple things, even abroad, without any problem. But to get a ticket for a huge concert one day before it took place was impossible (anyway, the event was sold out since months and I did not really expect it)
-- I went to some AMEX organized events (dinners, wine tastings, all published via their website or magazine) and must say all of them were VERY nice. Also, each time there was a staff member of AMEX Life Style service present at the event --- and I have to say all of them proved to be very nice people. At least, all of them were able to deliver the imagination that they would really think their Centurion members would be somehow "special" persons
