In my experience the one thing I still really hate about the Ipad is that the download limit over 3g direct is 50mb. Now for most awesome apps/games its just not sufficient. I still find the best solution is to put in the extra bucks and get a mobile 3g router (battery life between 3-5 hours) if...
Nah, its not worth it - all the reviews reckon if you are coming up for a contract and you want an iphone going 4s is not the worst thing you can do (that is if you think that the 16/32/64gb versions, and the upgraded camera are worth it to you) .
I would say if you are currently an Iphone 4...