My iPad 1 was Wi-Fi only. It was fine, but I travel a lot and Wi-Fi is spotty at best on the road. I got 3G on my iPad 2 and love it. It effectively frees the device to be used more or less anywhere. I used it on the beach on Maui in January.
My take? If you use your iPad on the go, get the LTE model.
My take? If you use your iPad on the go, get the LTE model.