okay after running "rigorous" testing (playing a few maps with each) I can say, out of the main Br00tal Doom mods, the one I'm enjoying the most right now is Project Brutality
between the latest PB, Brutal Doom v22 and Brutal Pack v10, that's what I pick
Brutal Doom is the OG, the vanilla of the mods. No fuss, no bloat all killer. Just powerful guns and gorey animations
Project Brutality is the endpoint of what most people ended up modding their GZDoom with: it comes in with a ton of addons to create it's own experience already seasoned to taste. Good solid fundamentals, cool good guns and extra functions like grenades, quick melee, Glory Kills, weapon upgrades and higher tier monsters that you see the longer a mapset goes on.
Brutal Pack is somewhere in the middle with the guns and monsters, but what it does focus on is, bringing the Doom Eternal mechanics into play. So Glory Kills are way more focused on, you have dashes, the flame belch, chainsaw on cooldown, grenade all that stuff. If that's what you want, great I think it's the best implementation of those mechanics towards classic Doom (that isn't just straight up being GZDoom Eternal) but that's not what I want. The other two have some of these in, but they feel more optional, unlike Eternal and Brutal Pack.
I played Brutal Doom v21 so much that at one point it felt like vanilla Doom to me on GZDoom. Feels nice to finally have something else cohesive for that kind of gameplay. Project Brutality spent too long with a bunch of addons and optional files that ended up all integrated into the latest version, properly now.