Casino Player magazine reports PA slot payouts. I don't recall the exact numbers, but they are maybe 5% below AC slots.
I've been to Phila Park casino twice (a promo offer, of course.) The first time was before the current financial mess and EVERY slot machine was occupied! I was there, again, about a month ago, and it was still probably 75%. I don't ever think I've seen anywhere close to even 50% of the slots in use in any AC casino, even during peak season.
Phila Park is about 5 minutes off I-95 and Rte 1, in a densely populated suburb of Phila, and only 5-10 minutes from Northeast Phila (also densely populated.) Why drive 1+ hours, pay $5 for AC casino parking, and pay ~$10 in tolls for a few %age points difference in payouts, when you can drive a few minutes and park for free? Maybe some of these people are smarter than the AC casino execs who continue to remove table games and add more slots.