The thread title said IMPACT not tools. The DeWalt 899 is $229, $50 cheaper than air. Once you buy the hoses, fittings, and oil for the air tool, you could buy a replacement battery in addition to the two or three you could buy for the cost of an air compressor.
Typo on my end, but the content of my post still addressed IMPACTs. So don't know why you pointed that out.
$229 is for the tool only, so try again. $350
https://www.amazon.com/dp/B00X52TWA4/?tag=atomicindus08-20
And you can only buy 2 batteries for the price of the compressor, not 3:
https://www.amazon.com/dp/B00KQU1ENG/?tag=atomicindus08-20
Fittings and oil come with the tool and OP has a hose already. If not, $6:
https://www.amazon.com/dp/B000BOAB9K/?tag=atomicindus08-20
That's a bet I'd take. A $150 HF compressor under heavy use will seize a piston before an M18 battery will stop acceptably charging and discharging.
If we could set up a controlled test, I'd love to wager. But we both know that can't/won't happen.
And sure, the guy who never changes the oil, but with regular maintenance, that
shouldn't happen, just like getting a lemon battery.
A battery being "dead" can have multiple meanings too. Certainly stop acceptably charging and discharging are one. I consider a battery dead when it's work time significantly shortened, or doesn't perform at peak performance any longer. Others may differ, but the conditions I stated mean the battery is holding up my job with more changing and charge time. Once again, under heavy use.
I've seen these li batteries take a dump in a year, this is under
heavy use, which is apparent most don't put these batteries under. Lugs in the rust belt are no tough task. Especially if the lugs are getting serviced regularly. But if you don't use them under heavy load all the time, I know they'll last longer. Hell, I still have nicd for my old school dewalt 1/4 impact. But that doesn't get used on cars. It hangs pictures, so of course it'll last longer.
My comments are on the thread title and direction, which has turned into a blanket statement that air impacts are dead (as others have pointed out, just the way the Internets works). As much as everyone likes their new to the market cordless tools, they haven't killed anything but their predecessor. And as I said before, cordless has their place, just like air. There's no single tool that's king of the hill for all repairs for all people. I certainly couldn't tell people what works for them or what doesn't for their situation, and vice versa.