Make sure to also check out the disc-binding system - see e.g.:

http://reviews.shopwritersbloc.com/tag/disc-bound

https://en.m.wikipedia.org/wiki/Disc-binding

I'm a huge fan: invented in the first half of 20th century, the system basically blends the benefits of a ring binder (easy adding and removing of pages) and spiral binder (notebook can be opened flat, and you can write on both sides of page easily). Also, it's IMO just kinda crazy and counterintuitive how paper has enough strength to be able to stay bound hinged on unclosed holes... (!)