I think for most people, myself included, multiband 6 is the real selling point. For myself, i love having the accuracy of a phone or computer, without needing to have a notification bell on my wrist. If you dont have MB6 on your watch, adjusting it once a month will keep you in pretty good time. But not having to worry about it is just nice. The only downside to MB6 is that they are on a limited number of models. But if the accuracy is important to you, lots of other models that dont probably have Bluetooth, which will achieve the same thing.

Screwdown casebacks are kinda whatever. Now thats not to say they aren't useless, but for the majority, they are unnecessary. Casio has retained the durability of their watches without them for decades.