They have definitely blurred the line between the two. For me a pac boot has a rubber/water PROOF bottom and a removable wool/felt liner. They are designed for minimal walking an mostly sitting in snow. I always have an extra felt liner and trade them out daily to dry

I hunt Colorado every year, and if hunting when it may snow, I will take the pacs, but hardly ever them. That said, I normally hunt in September or early October.

In archery/muzzleloading hunts in September, I take a light pair of uninsulated gore tex boots and a 400 gm insulated. That covers me for any situation. I used to wear a sock liner, but since the introduction of merino wool, I just use one of them. Thinner in the summer/warmer weather, and thicker for colder weather. They are comfortable and haven't caused any blisters (unless your boot isn't broken in)