1/2 cordless impact opinions

Been looking at cordless impacts to carry in car for emergency tire changes. I can't justify paying the prices they want for DeWalt or Milwaukee. Porter Cable seems to be the cheapest I have found. Any opinions or suggestions?

We have an inverter in Fred (the 59 Ranchero) so we can use 110v tools and accessories when we want.
It also has USB ports for charging phones and such.
Just a thought.