I just installed one these yesterday. A bit of highway driving and a bit of stomping on it to see how it sounds. Throttle response seems better and the CAI is very quiet which isn't surprising as it is fully sealed like the stock air box. Doesn't sound much different than the stock unit. Had a K&N HAI (hot air intake) on my truck briefly and there was a loss of low end that was noticeable off idle which the dyno chart for that intake shows. This one also shows a loss to about 2200 rpm I believe (would have to check the dyno chart on the AFE website) but I'm over 2200 pretty quick so not a big deal to me - from a seat of the pants standpoint it's not noticeable that there's any loss down low. All CAIs have this loss of low end and give more power in the mid to high ranges but this one seems less than most.
Fit and finish is great but on install you may have to cut a zip tie that holds wiring to the bottom of the stock air box which you'll be removing. The install instructions just mentions the A/C line brackets you need to remove and secondary A/C lines you need to unclip from brackets on the stock air box.
Can't speak mileage as it just went on there but not expecting much.
Bought it to go with a Hemi Fever tune and probably wouldn't have bothered with it otherwise. It is a pricey unit. As with any CAI don't expect any miracles from just adding this one part and you won't be disappointed.
Much better option than the K&N unless you want the intake 'growl' that the K&N has in abundance. Or, of course, you don't want to shell out the additional cash but still want an aftermarket CAI of some type. I believe these are still the only two 'CAI' options for the 6.4 on the market at this point in time. Since the K&N unit isn't sealed, I guess the AFE unit in the only real CAI option other than the stock box.
