I took delivery of a new 737 NG (http://www.precisionmanuals.com) yesterday and I must say it is a fantastic aicraft to fly, it does not have a GPS like the other aircraft in FS but it does have a very good Flight Management Computer. The cabin also sounds a little more realistic, after flying this I don't think I will be going back to the default 737. It also comes with a set of liveries.
It does have a GPS, but not in the traditional sense. The GPS is part of the navigational system of the FMC. Instead of the GPS being a seperate entity it's a component that the FMC uses to determine where you are.