Has anyone tried the new Rockwell?  Seen some recent ads on the tube and it sounds good. Lithium 3/8" with 800 lbs. of torque and a full lifetime warranty on the battery.  Don't know the price but Rockwell stuff has usually been heavy duty.

I bought a dewalt after going through a harbor freight special.  Even new the batteries on the HF gun were only good for one or two tires.

I have had the dewalt for 3 years.  Both batteries still going strong.  It was just under $300 though (kinda pricy).

I have a milwaukee impact going on 4th year. Works great, but it is HEAVY!! Bought on Amazon w/2 batteries, charger, and case for $289.00

The teams I've worked with have had snap on impacts for years. As the "gun guy" on race time tire changes, I've yet to come across an impact in all my years as a crew chief that can match the power, durability, and torque (in real world applications) of the snap on piece. Down side is they are very spendy.

BUT...

Now that I'm starting my own program, I needed to find something and for the price of the new Craftsman C3 impact I got ($99), I was extremely impressed with the speed it spun the lugs and the torque it had. It is the only one I've come across that gets close to the snap on in those dept's. I think it might even be good for race time tire changing. I've tried Longacre, Dewalt, and a number of others I can't remember. Snapon was the best by far. I think this new craftsman piece is by far the 2nd best.