This type of chain has been around for some time. This is a true "chisel" or square ground chain. What most call chisel chain today is if it has a square corner at the cutter top but the belly or gullet of the cutter is ground round. The chain you are referring to is the fastest cutting chain I've ever used and does especially well with big thick pine or any other kind of big evergreen such as fir and spruce. It needs clean wood however and is really touchy as it applies to sharpening angle and gullet length. It is best sharpened with a grinder. It may cut faster but one wastes alot of time keeping it honed just right. For the average chainsaw user as opposed to pro production, it is a rather pia to own. It is best not to sharpen this chain on logging sight but keep several handy for chain replacement then grind them sharp at home and you had better know what you are doing with the grinder for this type chain. If you are dealing with even the slightest of dirty wood, pass on it all together. Some "pro" stuff gets a reputation and then this info gets disseminated to the general public. Doesn't mean its best for the general public. Rarely do loggers cut up stems for firewood. They cut the tree down, remove the crown and on to the next tree. Give me the fastest cutting chain there is in this instance. They may cut to mill length occasionally but to go down a stem cutting it for firewood, one is much more prone to cutting some dirt on these logs. The company I worked for cut both mill stems and when it got slow, firewood. If I knew it was a firewood day, I'd never bring this chain along.
