Well, it's been five years since I posted this:
https://geekhack.org/index.php?topic=98563.msg2690117#msg2690117Since then, I've played DOOM Eternal and its two expansions The Ancient Gods Part 1 and Part 2 several times on nightmare (it's the best first person shooter in several years), and, in 2021, I played through every single original DOOM release, plus Romero's new maps: DOOM (plus The Ultimate DOOM episode 4), DOOM II, DOOM II Master Levels, Final DOOM (TNT: Evilution and The Plutonia Experiment), Romero's SIGIL, and the couple WADs Romero made as practice for SIGIL. I didn't do a pistol start on each level, but they were rather tough games nonetheless, and the level design is extremely creative in the later games. I wrote a review for my friend after beating each game in which I pointed out notable maps, and it was nearly impossible to describe the levels.
And this year saw the release of MyHouse.wad, one of the most creative and technically ambitious maps made for the game. This game has more longevity than any other.
Happy 30th, DOOM.