Me and my girlfriend went 5 nights this year, we travelled from the UK so I drunk pretty much every night we were at the event , some nights more than others and not once did we have any issues with any security, police or bar tenders.
There were times when she wasn't drinking that I'd hand her my drink to hold while I went to the restrooms or fumbled in my pockets and we had no one come over to us at any point.
Also I had my passport for ID, because at HHN25 they wouldn't accept my drivers license due to it being slightly snapped, however my girlfriend used her UK drivers license this year and didn't have any issues.
I feel like there's not a lot problems compared to the amount of alcohol and the size of the event, at least less than you expect compared to similar events with alcohol. I honestly expect more than there is every time we come, and we always come back feeling like people are making some of the stories up or exaggerating, but as someone mentioned people are more likely to complain than to compliment a chilled event.
Only one issue we did come across was one Scottish girl was very rowdy, pushing the queue fences in line for scarecrow and lots of shouting. But security were watching her and sent someone in the maze after them, and before us to keep an eye.
Edit: Also apart from it being more tedious to get mixed drinks, like vodka lemonade etc. It was not any more difficult to drink, or get a bit loosey goosey, we did Springfield stay and scream and just sat at duffs every time, was great. (Which btw do have vodka and other spirits/liquor)