I have an AirCharger. It takes about an hour to put the pieces together the first time and about a half hour to then remove the factory air box and install the intake system.
You should know that the AirCharger, like most of the other aftermarket "cone" type intakes is LOUD. Let me repeat that -- it is LOUD when you get on the throttle. If you like that, go for it.
My wife does not like the noise. Most of the time I run a simple K&N drop in filter with the "airbox mod" (cutting out most of the air snorkel tube inside the airbox to direct air flow up into the filter rather than over to the side of it). There is no increase in noise.
Objective gains based on my G-Tech accelerometer: 2 horsepower with the drop-in. 10 horses with the AirCharger.
BTW: Once the AirCharger is assembled, you can switch back and forth between it and your factor air box in about 20-30 minutes.