Did the tour last Friday as part of a few days hosting a student group (definitely wouldn't recommend herding sixteen students through a football stadium on Friday afternoon when you've got a bus waiting and are on a tight schedule!). I'd done it with my two pre-teen cousins a few years ago and thought the self-guided arrangement was decent - to an extent, I could manage their pace and the photo-opportunities, etc. Felt a little different as part of a larger group though, and that it would have been a much better experience if we'd progressed through as a group - there's probably quite a lot of the handheld AV stuff that could have been skipped in favour of in-person commentary, with signposting just to some key moments (pre-match YNWA for example).