Yeah, the base game will let you know.Black Labyrinth is a DLC for Amid Evil So I'll buy that first see if I like it enough to buy the DLC
But having played two times now, i think the DLC is indeed better. The base game sometimes had the retro FPS problem of searching for a key for too long, and getting lost in the process. With the DLC i did not have this problem yet - the level design seems to guide me better. DLC also is a single connected 'story', unlike the base game which is divided into worlds and a hub.
Level design is the primary strength. It's varied, interesting to explore, but mainly everything in the game seems to be made with a gameplay first priority.
Every pathway has the right width, every projectile and enemy has the right tempo, combat keeps interesting, fun and rewarding at any distance.
Judging by gameplay and experience, this is indeed the best FPS ever made to me. It's like the game of my dreams when i've played Quake back then. I guess you won't regret.
Can't help with VR, but desktop experience is perfect.