I've never tried the loom bands, don't really know how they will work. I tried the spiral bands but did not like them. They were hard for my arthritic hands to get on and off. The other challenge is getting the correct size.
I prefer the zip ties. I can adjust them to the correct size when i first put them on. With any hard band you have to monitor them, the chicken's legs continue to grow and get thicker. I find the zip ties pretty easy to cut off when I need to change them. I could get the spiral bands off but, as I said, it was a little harder with my hands.
I never had any issues with the chickens pecking at the spiral bands or the zip ties. I would not expect those loom bands to be any different as far as pecking. I don't know how well they will stay on or if you can tell if they are getting tight.