I have been Starwood loyal for years but am now finding myself switching a lot of business to Hyatt. Although Hyatt has a lot fewer properties than Starwood; I find that even as a mid-tier status (Plat with Starwood) I am treated exceptionally well. It is never the "big" things; but rather the small things that make a difference to me.
I don't feel that Hyatt nickels and dimes me to death as Starwood has started to do and every Hyatt I have visited the staff has been absolutely superb in terms of friendliness and professionalism. As of late it seems that I hear a "yes" more often at Hyatt than the "nos" that I continue to hear so often from Starwood staff these days.
This is not to say that I won't continue to be *wood loyal, I love the program quite a bit, but I have moved business (20 stays so far) to Hyatt. BTW - I am a leisure traveller only this year.