Since Half-Life is free for everyone and Steam updated a few things. Here’s a tip to enable the “Hi-Def” models, if you don’t like the original poly models.
disable Options-> Content -> “Enable original models”
It’s a little counterintuitive from the original way, but steam hasn’t updated their support page yet.
https://help.steampowered.com/en/faqs/view/6CF4-96FA-BF4A-329D
If you’ve never played HL1 and already own black Mesa but haven’t played it yet, is it better to play BM or the Original?
Black Mesa takes a few creative liberties, and very much feels like its own experience. I’d call it more of a remaining than a remake.
Personally, I think the original is much tighter in its level design and pacing. Black mesa changed a lot of the levels and puzzles, sometimes for the better but not always.