question about doors and weight

[kenwood guy]

I was talking to my co-worker one day and we started talking about trucks and the weight he drives an older long bed dodge pick up truck with an extended cab.. now get this both of the extra cab doors dont open on his truck because of that he has to flip his seat back to let someone in the rear guess what the trade off is???? his truck is almost 2k pounds lighter!!!! then his wifes truck,she drives an X-cab dodge truck regular bed and all four doors open up like my silverado needless to say his truck runs alot better and its a long bed!!! I was wondering if the chevy trucks had ever done this kind of setup, if so the truck would be much lighter do to less reinforcement at the top and bottom of the cab plus can sill seat 5 people now im kind of wishing my truck was a 3 door, I maybe would have lost 1k pounds?????