I have one of each. The 5.3 just didn't have the power I was looking for in mountainous terrain. And even with a 5500 lb trailer I was exceeding payload capacity. My 6.2 pulls a lot more effortlessly. In normal driving conditions, the 6.2 has noticeably more power and is a good bit faster than the 5.3. The 5.3 will now be relegated to pulling my 2800 lb trailer, and even a trailer that small still has the truck right at its payload capacity. So forget about so-called max tow rating. It's a nonsensical and irrelevant bragging rights number only. Try pulling anything at the max tow rating and you'll be exceeding every other weight limitation there is, ie Gross Combined Weight Rating, Gross Vehicle Weight Rating, Gross Rear Axle Weight Rating, Payload Capacity and Tongue Weight Capacity. In fact, when someone tries to quote their vehicle's max tow rating I immediately know that they don't know squat about towing.