Restaurant Musings - To Tip or Not to Tip for Take Out?

We have several new upscale chain restaurants in our area and we have become dinner lazy lately and have been ordering take-out. My favorite of the lot is Chili's because they have really made a nice guest experience of their Take Out. There are parking spaces just for Chili's To Go and a separate entrance and cash register as well so I don't have to wait at the bar and try to attract the bartender's attention so I can get my take out order. My angst is always - should I tip for Take Out? If I was eating in, I would certainly tip, of course. But when the restaurant seems to do a really good job of putting all of my food so nicely together in special take out boxes, including all accompaniments such as rolls and butter and dressings, I feel guilty just paying what is on the check. Does any one out there tip for Take Out?