It's a bit less busy but nothing too crazy. But if you go during a special time it's always wildin' (like it's packed around Halloween, New Year's, etc.) idk about Christmas Eve because I think I've NEVER gone exactly on Christmas eve/day just because I'm home with family then.

Gone a few times just before Christmas tho and also on New Year's eve a few times and it really is a NICE vibe/atmosphere

Like the casino(s) itself aren't normally toooo different but the spirits are high, lots of good energy & fun from everyone etc. Yup plenty to do tho and even the same things still feel different with each experience, I feel like you've said the same about London / those Christmas markets especially
Really good combo with the poker & Blazers doing well at the same time, such a feel-good night

And lol yeah feels like my one good thing about 2020
