This entire post has made me want to avoid the PB's all together.
First of all, understand that most of the people who posted in this thread are the kind who will hit every hole. There are a few legal spots where you can get into deep water, but for the most part, the Pine Barrens offer a network of unpaved sand roads you could drive in a minivan or even family sedan without major problems.
It all depends on what your idea of a good time is when out wheeling. Aside from the mud holes and occasional loose/sugar sand, you could drive around all day in 2WD without concern. When there is water, if you're a sane person and don't know the terrain well, you need to get out and check to see how deep and whether there's any bogged-out ruts. This means wearing high, waterproof boots or getting your feet wet (I usually opt for the latter). If you are stock, anything over 12" deep with a solid bottom should be avoided. Use 4WD Low, disable ESP and drive slowly through water without causing a splash, and slowly add power as you feel resistance. Airing down your tires will help with traction and smooth out the ride. You don't need to raise your breathers (though it's easy and a good idea) and you definitely don't need a snorkel if you use your head.
The Pine Barrens isn't the only place that will cause you to do maintenance on your rig. Whether you're banging and dragging over rocks or splashing through muddy water, you need to get underneath and clean off the mud, sand, dirt, whatever you pickup while wheeling, grease what needs to be greased, and check/adjust what needs to be adjusted. On a stock Jeep there's not much that needs greasing/adjusting, but on a lifted Jeep you've got jam nuts, pinch nuts, rod ends/flex joints, sway links and other things that need to be checked, periodically tightened and greased. If you don't do this on a regular basis -- at least once every three months or so -- you're going to wear out or break something before it's due.
There's lots of quite, isolated and often beautiful scenery in the Pines. There's also a lot of historic ruins and barely visible ghost towns. If you're driving through the Pines and see a grassy meadow, chances are excellent that used to be a town 70 or more years ago, especially if it is near running water. Iron furnaces, mills, cranberry and blueberry farms, paper mills, spas, resorts, even a ranch once dotted the landscape. Now all that's left are open fields, maybe the ruins of a furnace or foundation, rock walls, almost buried slag heaps and abandoned bogs.
In present day, the Pine Barrens supports a wide variety of unique plants and animals. It is a favorite place for bird watchers and geocachers. There are several species of wild orchids and carnivorous plants.
If you like crawling rocks, hill climbs, technical wheeling, the Pine Barrens isn't the place for that. But if you just want to spend a pleasant day in the woods with your Jeep and some friends, it's not a bad place to go for a day trip or even a weekend camp out.