I also drove the 5.7 and it is nice, plenty of power. However, I was trading in my '02 Avalanche with an 8.1 Liter BA V8, so I thought the power was about the same (not the gas mileage though!). I went with the 4.7 because I wanted a 4X4 and they are a bit hard to find around here. i had to go with the better deal and I don't think the power drop off, although noticable, from the 5.7 to the 4.7 is that great. My 2 cents.