I build RC planes/quads, where 80A currents are not uncommon, and I use XT60 with 12AWG wire. I don't know if there's a crimped XT60 connector, but all the ones I've ever seen are soldered. I don't know why you'd crimp, it seems to me that soldering would be more efficient for high currents due to the larger surface area that makes contact, but I don't have specific data one way or another.