As I stay purely for leisure I do not have that many stays in any one hotel group. Having said that, I have only one stay planned for the whole of this year in a Hilton compared to 18 stays last year. I have moved all my usual stays to Hyatt and Starwood and am keeping my IC stays where they are.
I have found service getting worse in Hiltons and the quality of the exec lounge has gone down drastically. I had a great stay in Evian on points but most other Hiltons I've stayed at in the last year or so have been disappointing. Maybe it's only the UK hiltons but I feel they have been overtaken by other groups and now feel quite downmarket.