@Kodiak Kid, been a while since I've ran an 044, but I will tell you it's way lighter, and I would suspect cuts the same or faster. Factory ratings seem to be very close hp wise. I'm not really a stihl guy, and it cuts with or a tad faster then my 562xp husqy. It's really hard to give an honest opinion on it with such few tanks through it. Steve said about 8 tanks and they wake up more. I know it's fast with a 20" on it.
A 346xp is 47 or 50cc. Depending on edition. I have an oe with a ne top end on it.
I have no idea why you would want to run such a short bar on a 660. Especially in .325 pitch. Thats just asking for issues, and imo a waste of time, when nearly any smaller saw will run the same in the same wood. Never got the big saw little bar thing or the little saw huge bar thing.
@djg james square chisel is another type of chain grind, where instead of a round chisel you sharpen your cutters with a square, goofey, or tri square file. It's a very efficient cutter but dulls quickly in dirty wood. It takes considerable skill to file it by hand and square grinders are expensive and used are rare as hens teeth. Now don't let me dissuade you from getting some, even in crap stock form it's way faster then any round grind out there.