Its about £100 more for the GPS/3G model. An external GPS is £60-70 so I think the internal one is probably the better option as it saves worrying about charging an extra set of batteries for the bluetooth GPS, and you can use 3G.
I did wonder how much memory I will need in the iPad. I have 16G on my iPhone and only a little over 1G unused. I thought that 16G might be a little light for an iPad mini.
Anyone have any suggestions on how much memory to purchase? (it must be the most expensive memory in the world!)