Review from someone who actually played it on Nightmare unlike 99% of this board who doesn't play anything.
POSITIVES
Game is NOT slow, far faster than 2016 and can definitely be just as chaotic as Eternal
Gameplay is fun once you get used to it
Exploration is rewarding
No weapon mastery skills, instead they just give golden skins now, which is better for replayability
Twice as many weapons as any Doom game
Possibly the most enemy variety of any game in the series
Weapons are mostly fairly balanced
Easily has the best bosses of any Doom game
Mech/dragon gimmick levels are okay and very few and far inbetween so they don't overstay their welcome
NEGATIVES
Extremely underwhelming soundtrack, not a single memorable song
Weapon swapping is too slow
No fast travel for secrets after you clear a level
Basic shotgun is far better than the super shotgun
Shield runes and melee weapons are very imbalanced. The last melee weapon you get far outclasses the other two and same with the last shield rune you get being leagues better than the others
Overall pretty good and close to Eternal. I'd give it an 8/10.