Yep, they've been a staple for me for years, although I don't like the original egg+mozz recipe. That was way too eggy and salty for me. There are lots of adaptations and we had this thread going on: Chaffles recipes thread.

I didn't like my everything bagel seasoning, because it was way too oniony and salt-chunky. I might try it again sometime running it through a spice grinder and adding other spices to balance it out (more poppy seeds, sesame seeds and garlic powder)

One fun variation I liked was stuffing chaffles for a turkey sandwich. Cook some onion and celery in butter, add that and some poultry seasoning to the batter.