Hi Barbara,
I did the PFF for 25 consecutive years from 80 to 05.
I did "heavy" camping for a couple of those early years ,but mostly did tent camping.
Marymac's advice about early arrival was dead on.
You'll find motorhomes & campers lining the roads,waiting to park all day Thursday & most of Friday.
Be prepared to wait.
You will find a certain element in the camping area that is there only to PARTY.Some never venture out to listen to live music at the concert area.Sad fact,but their loss.
It's doubtful the these folks would be any bother to you in heavy camping as the vehicle area tends to be a bit more subdued.

The PFF is an event that you should experience at least once in a lifetime.
But don't expect a quiet little "intimate" folk festival.
In the 25 years I attended,the PFF had grown quite large.
I'd always camped with a small group of like minded folkies who got in early & claimed some decent real estate.(We were never those "big tarp" people)
In the later years,I'd always run into some poor soul arriving Friday evening with nowhere left to pitch his tent.

As for the music.
I was never disapointed.
True they do seem to book more folk/rock now than before,but there's always been a fair share of the trad.stuff in the program.
Not to mention the music being played in the campground at night.(They no longer allow fires though)

The last year I attended 05,they changed the Sunday concert.
It started in the afternoon & ran straight through until 10 pm.

Other than that,I can only say,be prepared for rough/hilly terrain,& any kind of weather.
And very little shade.

They changed the dates for the PFF in 06.
It now conflicts with a fest I attend in n.central Pa.
I may return to the PFF for their 50th in a couple years.

D.B.