Anyone running Sway bars on the NNBS trucks? I've read a little that the rears help while the fronts are questionable for the NBS trucks. Anyone with recent experience on the NNBS?

Secondly, anyone have experience with sway bars on the NNBS AWD Sierra Denali?

 

I put a Hellwig 7800 rear bar on my '08 extended cab 3 years ago and it made a big difference in cornering. A little while later, I replaced the stock 32mm (1.25") front bar with their 1.5" 7685 bar. The front bar made a little improvement, but nothing like adding the rear one.
I think there were 3 different stock front bars in '08, 32, 34 and 36mm. Not sure what there is nowadays. If you have one of the bigger ones already, you may not see much difference by going aftermarket.