I won't be renewing this year due to reduced travel. But my thoughts below based on London, the EU and US travel..

Upgrades - I had incredible consistency(90%+) in getting suite upgrades where they were available, from W's, RC's JW's and Sheratons. However, I will caveat this by saying I also had 90%+ success rate as platinum and titanium.

Your24 - I never used this after seeing bad reviews. However I did check-in at 6am as platinum once just by calling ahead, so assuming a room is ready I don't think they really care - it shouldn't change anything for them at all.

Phoneline - Never really used it, booking myself is easier/faster and as there isn't a dedicated ambassador I didn't see any point trying to build a relationship with person #231 and having seen Amb reviews about any personal touches disappearing I didn't bother.

Email - I did use this once. For some reason I am banned from just 1 Moxy hotel in NYC. I made a reservation here before I knew, booking seemed fine on the phone but upon arrival I was told my booking was cancelled. Obviously I was unaware of this and have no idea why I could have been banned from the property so I emailed my Amb to find out why and they were not able to provide any detail - so again, am I really valued as Amb? Surely they should convey the detail as apparently I'm a cause for concern for their hotels!

In summary, I don't see any soft/hard product value for being Amb in London, the EU or US. There's probably a single digit % increase for suites but that's about it. Obviously service in Asia is apparently much better, but I didn't travel there so can't speak on it.

The best value I had was for my own giggles when I checked in (as a younger looking more casually dressed guest) and seeing the half-asleep clerks perk up as Ambs are still somewhat of a rarity - and rightfully so based on the value I'd say.