True, but if the vinyl version has double the amount of dynamic range as is often the case, at the very least that's a clue that it's not a lazy CD transfer. To get deeper than that you just have to ask around. The Steve Hoffman forums can be a good resource, or just Google. And of course you can always check the Classic Wax section.
I wish SH had a bigger Metal community. Most of it's either Grandpa Metal or not heavy enough. Most of the new stuff they like only goes to about Mastodon tier when we're talking heaviness.
Althogh there's a few Drone and Stoner Doom nerds over there.