Well this will probabley sound like nonsense but I just checked out three chains Oregon ,Arbor Pro and Stihl .
The Arbor pro and Stihl had thicker tops plates and a less square transition from top to side plate on the underside of the cutter than Oregon .In addition the side appeared to be slightly thicker near this transition than Oregon .
The Oregon as has been stated is designed to use a 10 degree up while the other two are straight . It would be my assumtion that possibley this 10 degree would form a better working corner on that slightly different chain design .
One must keep in mind the side of the cutter is what does the work and the top plate removes the chip but the key to it all lies in the corner of the tooth .If that corner is not correct the chain will not cut as well as it should .
To reiterate from my own experiance a chain that's supposed to have a compound angle will cut okay straight .A chain that's supposed to be straight doesn't do well with a compond angle .One of lifes little lessons I learned along the way .