Re: Sendero II or PSS
I also have a Sendero, although it's an older model in .270 Winchester, and I also have had excellent accuracy with it. Best 3-shot group so far has been .187". Ironically, the worst group during load development was the group just prior (1.321"), and was exactly the same load. I shot 8 groups with 130gr Ballistic Tips during load development, and the avg. group size was .662" (this included the group where I jerked the trigger).
Shot three more groups doing a quick development with 90gr Sierra HPs, and the average size was .541" (all three groups were between .5-.6").
With all that said, comparing a PSS to a Sendero doesn't seem to compute too well in my mind. On one hand you have a Rem. 700, with a heavy barrel, mounted in a HS Precision stock. On the other hand, you have a Rem. 700, with a fluted heavy barrel, mounted in a HS Precision stock.
Of the two, I would probably grab the Sendero II, for the flutes and stainless action/barrel. Beyond that, I don't think there is much of a difference.