Couple of dually questions

[turbo350]

Looking over some of the dually threads has me going lol. Just wondering a few things about them 73-87 specifically:

-How much actual curb weight difference is there between your average 3/4 or 1 ton standard cab dually versus say my '78 Big 10 2wd (approx 4100 lbs).

-I know gearing has a lot to do with it and most duallys are meant for towing/hauling but do any of you dually guys have what you consider a "quick" truck when your running empty? If so what engine/trans/gear combo do you have and any mods?

-I know some of the pros of owning a dually but any cons in your opinion? besides having to buy two extra tires ,etc.