Buy a gas one. You aren’t going to be able to drill 1000 holes through 40″ of ice with a toy.
I run a K-Drill and fish 3 days a week all winter. I haven’t had to sharpen the original blades yet going into the second season. I also do NOT sit in a wheelhouse or giant heavy thermal shack and “wait” for fish. I punch holes nonstop chasing fish.
A gas auger that hasn’t been used in a couple weeks would be slower through 18″ of ice than my 8″ Milwaukee driven K drill if you take into account anything other than a 1 start pull every time.
Electric driven augers are here to stay. I run mine into 2′ of ice with no hesitation all day long. There’s a time and place for gas, but that will become a smaller and smaller segment of anglers as batteries and drills improve. Look at the number of K drills in just a few years being on the market. Imagine 10 years from now.
As far as the nills vs. K drill debate it’s pretty simple. K drill blades are made for durability, dirty ice, weeds, dirt, opening old holes, rough ice, etc. The nills blades simply won’t take the beating and stay sharp enough to cut holes for as long. For those getting sore wrists running a plateless k drill, I’d question their technique. I’ve never felt sore despite 50+ holes on a typical outing.