I updated from and iPad 2-32gb 3G AT&T to a iPad 3rd Gen 32gb Wifi Only, I guess some would say that is a downgrade. However, in the year I've had the iPad 2 I had the 3G activated twice for a month each and then hardly used it. I opted to get rid of my unlimited on AT&T though and go with the 5GB Hotspot which works out great for me. Even since doing this I've never made it to 2GB in a single month. The Retina display though was well worth it and I think the iPad 3rd gen with a bit more ram is a tab bit snappier doing most task. I sold my iPad 2 for almost what I had in it, so it was a win win.
I prefer doing the hotspot and just keeping my iPad Wifi, another factor is almost everywhere I use it, I have access to wifi too.