You have to be real careful comparing different sharpening methods. Raker height differences need to be eliminated, and that is difficult if you don't have a raker grinder. My Silvey raker grinder has been worth 100 times what I paid for it. Most square sharpening of chisel chain is not correct. Guess what? Most sharpening of chisel chain round, either with a file or a machine is not correct either. We've moved over 15,000 cords of u-cut wood off our own property, mostly oak, and I have sharpened over 1/2 of those chains. I've offered to make this bet at least a dozen times: I take your sharpened chisel chain, sharpen it right, and mine will out cut your sharpening in the same wood, same bar, same powerhead, same chain, by at least 2 to 1. I am frequently willing to bet $5,000 on that if I first get get to look at your sharpening. If you know what you are doing I won't make the bet. So if you use a Silvey, Simington, Foley, Ziegelmeyer, Doerr or other grinder that sharpens chisel chain square I won't bet you. There is a Stihl shop nearby that is clueless on sharpening, and a mutual customer says my sharpening out cuts the saw shops by a 10 to 1 margin. I generally don't offer this bet unless I know my sharpening will out cut the person I make the bet with by at least 5 to 1. Believe it or not, I find piss poor sharpenings all the time where this is the case-and many are from "professional" sawshops.
I believe that a correctly sharpened chisel chain, sharpened square will cut at least 25% faster than that chain sharpened round.