I think key here is, some use heavy weight tomes. Other quick and easy, or in between but definitely useful. They help to keep all the ducks in a row and so, updated to keey track of facts, things like jewrally or just little stuff you might forget. Now though, definitely somthing that needs to know your audience, know what you want, and know how you gonna achieve because a bad CS sheet is a real intrest killer. It's a concept you need to adjust as you go, what works for one will not work for all. Though definitely favour keep it simple, even if heavy you do not want to have to spend 10minutes just working iur what goes where. Easy to use does not have to mean short. If you need a full appendix guide and supporting documents to fill it out and just to translate the CS. That is bad. Supporting is fine, but the CS should be able to be filled out without needed multiple sources just to make sense. The CS needs to be able to stand on its own and be understood. A complicated RP will need supporting info, but that info should not be used to prop up you failing to design the CS correctly. Basically like a logo. A good CS should be simplely laid out , easy to identify the companants and you should be able to fill it out without tricks or trap sections.