What do you intend on using it for?
I have the 4 and find the GPS is adequate for my needs, but I don't using it for driving. Mainly for apps that need "Location services" - such as facebook and the like, where only an approximate location is ever really needed.
Having said that, I'm off snowboarding in a few weeks, so will be using it extensively then to plot tracks and collate other data. Combined with a decent tracking app, I fully expect it to meet my expectations, and am sure that it will.