Comparing a 1/2 Ton suburban to a 3/4 Ton truck is apples to oranges.
Having owned 2 1/2 Ton 1500 series suburbans, it is a night to day difference with the 3/4 -2500 series Suburban which I have now. For starters, the 2500 has leaf sprung rear suspension, my suburban barely squats when the trailer is hooked up, before I tension the weight bars. The 1/2 Ton would squat severely. The engine seems to work less, but that could be from the 6 speed heavy duty transmission, higher rear end ratio, or the 6.0 engine. It is all around more truck. The rear axle is a full float heavy duty axle 8 lug.
I wish Chevy would make the 3/4 Ton available to the general public again. As I understand, it is only available through the fleet purchase program.