I've flown there round trip a couple of times this fall (ie from Maryland to Philly to pick up friend/s, out to do something, back to Philly to drop them off, then back home to Maryland).
Never particularly push times (once Labor Day afternoon and evening, once a random Sunday afternoon, departing Monday early afternoon). Small airplanes (C172 and DA20).
Philly approach was very friendly; you'll be vectored to final and asked to maintain best forward speed. I was VFR each time, and they were even willing to work with me one day that was pseudo-IFR (ie a couple of low scattered layers meant they were using the ILS, though VFR flight was possible).
Tower was fine; the only hiccup I had was the first time departing, stayed on the ground frequency after being instructed to taxi to an intersection which (unbeknownst to me) was the queue for departure and the tower's domain. After no calls for me and another plane that got to the intersection (via a different taxiway) after me taking off before me, I figured out what was going on and changed to tower. No harm no foul.
Atlantic is fine. $10 per landing, $20 security fee, $40 facilities fee waived with some amount of fuel. Includes first overnight free and a nice crew car. They let me depart without paying when I said I was going to come back and buy fuel later in the day, and the total of the two fuel purchases was enough to waive facilities fee. I don't know; they seemed flexible as far as I could tell. On the second trip, they "lost" the charge one of my fuel purchases. I pointed it out, and they waived my security fee.
