there are plenty of great discounts/benefits and possible/confirmed upgrades. lots of info/examples/etc in the luxury hotels forum, and the amex forum, including in the stickies.

but its no different from anything else, you just compare the offering of whatever partner/etc to the true best available rate.

and like doppy was saying, the room you book / room you might be upgraded to does matter. most of the time, if youre booking the base room for example, its not necessarily unlikely for the next room type to be sold out. or at other properties perhaps the base suites sell out fast, so if your upgrade states an upgrade to one, you shouldnt be surprised if it doesnt happen.

as long as youre not paying any more overall (unless you have the potential for a very valuable upgrade) i dont see how there could be a problem.

also

1. there are confirmed upgrades offered by many programs
2. confirmed noon checkin is offered by some FHR properties

you are getting a confirmed upgrade and full breakfast through virtuoso for your upcoming le bristol paris stay, correct?

finally, i see these things as the SAME as status for airlines/hotels in one respect - OP UPs. (operational upgrades)

you WILL get an upgrade (like if they have to put someone in the presidential suite) before an average person off the street.

during summer 2006, i was (pre)upgraded from base room to butler floor at sheraton park tower in london, as spg gold, on an award stay. my understanding is that platinums rarely get this upgrade on paid stays. that suggests to me i was the only guest checking in that day with gold+ status. (and i get spg gold via amex plat, which also lets me book FHR)

that sort of situation could work out the same way, if you are the only virtuso/fhr/etc guest.