The engine is the same on both but the transmissions are different. The Pathfinder has the Xtronic CVT and a fan for cooling the transmission. The Pathfinder tows 5,000 lbs whereas the JX only 3,500 lbs. I haven't driven the Pathfinder, but I bet the ride is similar, however the JX has more insulation, which makes for a quieter ride. The QX60 and new Pathfinder hybrids will have the smaller 2.5 Liter supercharged engine which should be adequate power, but the towing capacity will be probably closer to 3,500 lbs.
As for the features, they are really nice and will spoil you once you've driven the car for awhile. If budget is a concern however, I wouldn't think twice about picking up a Pathfinder. I'd make sure I at least have it equipped with the Navigation. We traded in a 2010 fully loaded Armada Platinum and really miss it (other than the poor gas milage).
If you are serious about purchasing one of the cars, I recommend you test drive several versions of each car. I love Nissan quality and after owning 7 of their vehicles and never having any serious mechanical problems with them, I wouldn't hesitate to purchase another vehicle from them.