I was recently travelling to Arizona for the Air Force. I was in a little town called Sierra Vista about an hour outside of Tucson. It's not known for anything other than being close to the legendary Tombstone.
In any event, while I was there I ate at a Pizza Hut Bistro. It was different so I figured I'd try it out and while I wasn't totally impressed, it was a step up from a regular Pizza Hut.
The interior decor was higher quality and more classy than a regular Pizza Hut and the menu was much mroe expansive.
It offered much more than pizza including several pasta and Italian sub sandwiches.
It certainly wasn't any healthier than a normal Pizza Hut but at least gave me a greater variety. Let's say that if there was one of each in my town, the 4 times a year I eat at Pizza Hut would be the Bistro type.