Originally Posted by Section 107

My experience with stay/park & fly was not at PHL but BWI: what I discovered is that depending upon the time of the flight it's simply not worth the effort. For an 8am Sat intl flight we decided to stay overnight at hotel next to airport. To avoid rush hour delays we left about 8pm, arrived at hotel at 9pm. To be at airport at 6am meant catching 5:30am airport shuttle which meant waking everyone up at 4:45am. On the return we had to wait about 45 minutes for the hotel shuttle to bring us back to our car. We could have stayed home and left for the airport at 5:15 to be there at 6, and caught the ever present long-term parking lot shuttle bus on the return and overall been more comfortable and still spent the same amount of time/money on parking.

So, yeah, depending upon the time of your flight, I recommend taking the mass transit the morning of.