I use far more tension with spirals than flat blades. And looking at you comparison, had I some olson spirals, I would run, not walk to the trash bin to toss them. Is that tear out for real? I thought maybe you had the blade upside down. I prefer Pegas spirals in #2/0 up to #1's. Pegas doesn't make #3/0 blades as far as I know, so I use FD for that size. I know some think it's against the rules but I cut 1 1/2" red oak with #1 and #2/0 spirals. Yes, it's slower and yes, I burn through blades. I tried FD new spirals and wasn't impressed with the cut or the longevity of the blade. They were a bit easier to control. Just an opinion from someone who has used spirals since the 90's 85% of the time.