It's funny, because at some Marriott's, I actually notice the exact opposite - I always fill out the slip but a lot of times I wait till the end to do it - however, at the most recent Marriott as soon as you sat down with the drink, the person manning the concierge bar would drop the slip right next to you. It was actually really annoying because it basically came across as 'don't even think about leaving w/out filling this out'. No big deal but kind of takes away from the 'honor' part.