While GPS on a FF is probably a great feature, it adds a lot to the cost of the unit. If I were in the market for a new FF, I would spend that money on a better image or color.
If you want GPS and have an iPhone or one of the other Android smart phones, the Navionics Marine app is $10 and works quite well. Check it out here.
http://www.navionics.com/NavionicsMobile.asp
Bob