As if you haven't had enough response yet, here's two cents. I started skiing Pico at age 4 and lived there every free minute when I was school age. Still ski there from time to time. I used to ski Mt. Snow once or twice a year when the circuit went there. Always GS on the North Face. I happened to go there this past weekend for the pacesetter time trials... again on the North Face. I refreshed my memory of the place as I hadn't been there in many years (not giving away my age). Mount Snow's North face doesn't compare to Pico. Average pitch is less, steepest pitch is less, and length of pitches is less than Pico. Giant Killer, top of A (if open anymore), the Pike (under top chair), KA... no contest. The problem with Pico is the long flat on the way to the bottom. They cut the first lift line wrong when they did it and screwed it up.
Besides that, on Monday I skied a great roller down the front side of Mt. Snow - great cruiser but I can't imagine skiing with speed on that on a weekend. B slope at Pico is great roller too as is the slope on the right of what we used to call Knomes Knoll.
A week ago I would have taken Mt. Snow because I hadn't skied there in years, but today I'd take Pico.