My invitation came at the perfect time for me to test it out to see if it is worth it. I've been plat charge since 18 and Cent since 21.
I do truly believe the Plat Charge is exceptional value if you travel.
However, the Centurion has its perks. The insurance is second to none. See above posts for some examples. I travel with my wife and she is an additional holder.
We have used it for two overseas trips and two domestic. We are about to head off for 5 weeks to Europe.
I'm shocking with planning. The relationship manager has been instrumental in organising and booking all the nitty gritty stuff that is too time consuming for me and my wife. All my wife does is say when she wants to leave, what she wants there and what hotel in which country. This includes all flights, trains, car hire etc. Nothing has ever been classed as too hard. In fact he seems to like a challenge if it brings an idea to life.
We have received:
40% off a hotel stay(paid for by Centurion) with exclusive centurion benefits in Singapore (5 star)
Complimentary pick up from home to airport, airport to hotel and airport to home.
Some benefits and rates have been cheaper than what the Amex portal showed. I spoke to my RM about this(why he can see cheaper) and he said it's something only they have access to.
The only thing I'm unsure of is the upgrade to hotel rooms. This will be tested in Europe as we didn't lash out for the room type for most, just the property to take advantage of the benefits. I have extension experience with what the Plat Charge offered with HHonors Gold/FHR etc.
In terms of the RM, unfortunately they really are limited to travel in my experience. I was hoping they could access or make things a bit easier for my wife with certain luxury brands she has no history with. But the RM referred off to a separate department which I'm not sure is available only to Centurion. I would think any Amex Platinum member could access. Which hasn't proved successful hence my thoughts around that.
Hope that provides some insight.