Again, we have plenty of experts on this here, and you may well be one of them... so take with a grain of salt... but I've always felt that where Jay cleans up is on the lingering N/NE flow from bombing coastals in N Brunswick, etc., throwing back moisture across SE QC and the extended St Lawrence valley and they being the first beneficiary of orography. Whereas the more typical W/NW flow is fairly evenly distributed, perhaps with Mansfield even outdoing them. And SB/MRG can occasionally score big on streamers especially, but for most upslope events they certainly average less than those others further north.
Even if I grant that Killington may do better than further S on westerly flow just purely based on relief, I've always kind of considered them between typical storm track paradigms, whereby they're a little too far removed from clippers and coastals that get the Berks and S Greens, and don't benefit from the seemingly daily snows that the big boys get. With temps closer to the former and moisture closer to the latter.