I am in NYC for a quick trip next month and have booked reservations for Gramercy Tavern at 9:00 and Blue Hill at 8:00. In terms of convenience the 8:00 hour is better so I will probably drop GT.
From what I have gathered, BH tends to be very well-prepared fine ingredients, without necessarily pushing the taste and experimentation envelope. GT is a very well-run establishment that tends to do the standard items very well. For creativity and originality, BH may take the prize for the two.
As for my tastes, in London recently, I did RHR and Pied a Terre, as well as Putney Bridge. PB was not in the same league. I actually found the food at PaT more interesting than that at RHR which was uneven. On the other hand the service and ambience at RHR was clearly 3 stars, even if the food was not. PaT's service was poor.
The problem I saw at RHR was a lack of sparkle and panache, with only a few dishes on the tasting menu being clearly outstanding.
With all of that being said, I wonder what suggestions you have as to which of the two I should keep and which drop. My thanks in advance.