There isnt much of a wieght difference between the 2nd and 3rd gen trucks. When I wieghed them my 95 was 7000lbs and the 04.5 was 7700lbs. Only 700lbs and one is a standard cab.
I love both trucks but the 12 valve is definatly the choice for driving through traffic. The power band is better and gets put to the ground better for acceleration even though the power output is similiar. The 6spd in the 04.5 is better for towing a heavy load. It all depends on what ya want the truck for.

 

I like my 06 more than my 02. Except 1 thing... The payment. Its a bit higher but its worth it to me. The truck feels more refined, it drives better, gets better milage, has tons more power, and is more shiney. I do miss the 2nd gen sound and tough look. I'm sure the 06 will grow on me.