I'd say the only weak aspect is the 1 drink per night coupon. Everything else is great imo.
If you want the full list from me: there are breakfasts I like better elsewhere (Rossini's, the huge Athenee buffet), I've yet to receive a particularly impressive upgrade at the St. Regis but acknowledge others have it seems, service (and drinks quality to an extent) in the bar isn't up to the standard it should be, furniture is not my style and is also a bit chipped/worn in places now I find, I also question housekeeping slightly as I wasn't hugely impressed to find lipstick marks on the reverse of the pillowcase last time I stayed there.