I went. The line to get in was absolutely ridiculous- I don't know if they had issues with the scanners or maybe didn't actually let anyone into the "holding" area until 2pm- but the line was all the way around to the bobsled.
Of course, I wait in line- 20 minutes later we're at the "gates" where there is a space between the ticket booths and the actual line where cutters just walk right in and "funnel". But- that's six flags, right? Ive rarely ever see it at Disney, Universal, or Sea World. But six flags... all the time. Rant over.
The crowds weren't bad at all, really- but I was with my 2 and 6 year old all by myself- so our rides never have waits anyway. But based on the food lines- it wasn't bad in the slightest. Snow Hill was the only wait- maybe 10-15 mins? We left around 6- so I didn't see the lights- I'll do that later this week when I have my wife with me and I'm not outnumbered.
I didn't get to do Holiday in the Park last year because the crowds were unbearable. Literally walked in, processed my pass, and left because it was insane! I'm hoping today won't be crowded. Planning on being there right when they open so I can get a few rides in and finally ride Justice League! haha