I thought the 18"er was the best, but of course you are getting a lot more momentum at the sweet spot and I prefer longer machetes for tough jobs anyway. ...and believe me, there's NOTHING easy about hacking through frozen seasoned hickory. It had plenty of knots and was hard as a rock. I was very surprised at how far those machetes bit in. Andy has tweaked the balde thicknesses a few times now, searching for the perfect one, and I think he found it. As far as a backpackable machete, that 12 is the bomb diggity! I have one and I love it. If I'm throwing one in the truck or picking one to use for heavy work on the regular, I'd get the 18"er. If I'm looking for a woodsbumming machete that fits in my backpack and is still and unbelieveable workhorse, the 12"er will knock your socks off.