in terms of functionality and power. iphone 4 wins hands down.
the appeal of the pre3 its purely based on aesthetics and ease of use. there isnt much the pre can do better than the iphone. and the one thing it can't do, is the one thing you need. downloading podcasts.
none of this is a deal breaker for me. im in the market for a phone, which I can text easy on, has a visually appealing design aesthetic (I really dont like the way the iphone 4 looks, or any android kit for that matter). I like minimalism, organic forms and no buttons on the front. I don't really use apps. and webos covers most of the basic social/media apps I may need, plus a few games which I will rarely play. also, if you are going to get **** coverage. it may be better to just get an iphone.
I'd put up with weak coverage, if I was paying 200-300 for a phone... but not 500+
for the price of the Iphone 4s, you could get an Iphone 4 + a pre3 as a backup device.
I don't know you, but Im pretty sure you, like most people wont even utilize the extra power the 4s has. and that gimmicky siri is being ported to iphone 4 anyway. there isn't anything that special about the 4s, over the 4. a better camera, so you can take better hipstermatic pics of your cats, or food or friends, an (innovative?? lol) AI feature, and some more power.
anyways, my point is. if the only thing you need the pre to do, it doesnt do. get an iphone. but if you were getting an iphone, just stick with the iphone 4, and use the money you save to buy something nice for the wifey