If you can afford the 3/4 ton, go for it, you won't have any regrets. With the 1/2 ton, you have the potential for regrets.
For me, the '09 Silverado was purchased when I didn't think I'd be at a point to purchase a trailer until "the next truck." Summer of 2012 opportunity presented itself, I got a trailer that would be within the limits, just under rear GAWR, but it is at 90% of GCWR. I'm okay in Texas, but where it runs out of "umph" is at 65 mph and into a stiff headwind.
I knew it would not take me to Colorado, but that was okay, still working, rather not use the vacation time burning 2 days on each end of time away. That was until my son's duty station changed from Ft. Hood (just up the road) to Ft. Caron in Colorado. With a reason to go to Colorado now, burning the PTO is a bit more palatable, I'm in the market for a 3/4 or 1 ton with diesel.
Hope these experiences help. PM me if you want more details on my numbers.
