Amazing experience, watching YTC on a big screen just hit different compared to watching it on your phone. The camera quality is great, their voices are clear and the fans screaming in the crowd aren't loud enough to disrupt the experience. The editing is high quality.
If you watched it in the cinema then you most likely heard people sing along (in my case it was not annoying and only when necessary) and it really is great. It's very interactive since the members urge everyone to join and have fun.
There are a variety of songs, which is why I think it'd give a non army an idea of what bts is like. Two people who aren't (or weren't, haha) into BTS went with me and they thoroughly enjoyed it, one of them was previously a BTS hater too. Obviously everyone has different music tastes, but there's bound to be at least one song that's enjoyable for non fans.
The ending is emotional for army's 😔 why did they have to make it sad? (Don't mean this in a bad way though, it really is a special experience).