I went with the AT4. I live on the coast where street flooding is frequent. I wanted the ground clearance.
I also wanted the power steps so I installed AMP’s on my AT4 and love them (actually like them better than the factory GM steps). They tuck up tighter to the truck and drop down lower for ingress and egress.
I have had several GM trucks and always felt they looked too low to the ground, but the AT4 remedied that and with the steps tucked up underneath it really looks good.