UPDATE:
I was cutting a piece of cottonwood, about 25" diameter. I Started out with 28" bar and RS full skip.
I figured after about 20 cuts, Id try out the square. Now, the square I got is full comp, so its not really a fair comparison. It cut about the same. So one should assume it would cut faster than RS full comp.
I did notice the chips coming out were longer than using RS, but seemed a tad on the thin side. I think if I take the rakers down to .30 or .35, it would cut better.
This is on my new 660 with an 8 tooth rim.