The 5.3L only operates in V4 mode when you're NOT touching the go pedal, or cruise control is on, which optimizes fuel economy with that combo. If you went GM and you don't plan to tow over 6K, the 4.8L 4 speed will work fine. Parts are a plenty, and you WILL get similar, if not better real world fuel economy over the 5.3L and 6 speed if you don't tow often. Lower displacement = better mileage, irregardless of gears. Besides, I'm on a GM forum for my Astro cargo van (other work service vehicle) and the 5.3 6 speed guys are happy with their purchase, but with the absence of the 6.0L now, it's a tough sell. The 4.8L without cylinder deactivation should also be less costly down the road for repairs. It ultimately comes down to personal preference, and by the sounds of it, you already know what you're going to buy. As much as fuel economy is important, it's capability that matters. If you want to tow 9K, the 3V 4.6l can do that with the lowest gears you can option. If you want a better ride, GM is the only one to go with, as its suspension is more compliant on nearly any surface. I'm not really biased as far as band name goes. However, the ultimate factor would be price. For instance, if I can get a GM for $35K, a similar Ford for $34K and a Dodge for $33K, I'd more than likely get the Dodge with the 310hp 4.7L V8 and 5 speed auto. Rebates are a plenty, so shop around. Price, followed by excellent service and support would be the ultimate buying factor for me.