score:3
It's a matter of preference, the Vermont route is a little bit faster, though a little plain in my opinion. I prefer the NY route because the scenery varies, you get to see mountains (Adirondacks) and lakes, the road isn't just a straight stretch and there are plenty of rest areas and service stops. The 87 becomes the 15 in Quebec which is a highway. Those have higher maximum speed limits than regular provincial roads and I'm a little embarrassed to say, maintained more regularly.
Also, and this is entirely subjective, it's my impression that the crossing at the NY border is more efficient.
Upvote:3
I'll answer for the QuΓ©bec part of it since I'm a local: The 15 will be much quicker but route 133 which we call Route des Patriotes here is very nice and you could take it up to Saint-Jean-sur-Richelieu if coming from Vermont.
And try not to get to Montreal at traffic hour, it can take quite a while to get on the island.