Given their traffic comes back to me through the Ellacoya, I don't see that it is important which of my connections is being used - are you suggesting that the direction of the initial packets has some effect - apologies if that has been suggested earlier...
Not the initial packet but every packet arriving at your PC on your ellacoya shaped line will of had some for of shaping applied to it, this could be *any* category from dirty bronze to shinny diamond and whatever else PN have made this week.
What i'm saying is as i move remote servers away from PN, i am finding them noticeable quicker when i connect to them from my line (my line has always been non-pn). Which i have found surprising as always they were traffic shaped as "gold" so i didnt expect any difference once they moved to other isp's that don't own ellacoya's. (just to confirm this is still crossing isp's not moving servers to the same isp that i am on.
How you can state that you don't see any 'sluggishness' no matter whom you connect and on which isp it is to, is incorrect, as your line is always shaped!