I'm not so familiar with later versions of Doom (beyond "II", really), but the creativity that went into optimising the effort/experience ratio of the original maps was definitely interesting. It's nice to know there's still milage in the old format (or not too distant direct descendent?) and I'm tempted to dig up the old binaries or compatible derivatives again.
One thing I noticed when I tried out a few of them, some months ago, was that modern WAD editors seem to over-sanitise my attempts to be tricksy. Back in '93-4 I used to play dimensional tricks with overlapping-but-not-sight-connected zones that worked well enough (give or take strangeness with no-clipping activated - which gave it another use!), but it looks like modern (public use) editors want to stop me making 'mistakes'.
I was on the point of just writing .WADs by first principles (for one thing, it would have saved all that time calculating the geometries of points around a circle(ish) path towards a given aim then hand-adjusting node coordinates, vertex-linking, zoning and making the appropriate edge-to-edge zone-edge sharing, I could have just generated all the segments procedurally).
(The in-house WAD editors probably were designed around the core team's needs. Sanity checking that knows about some of the little tricks involved, because if it aint the same guys involved in both sides, they can shout to each other across the desk-detritus.)
Of course, this is the difference between a creative artist (which I am not) and someone with a few ideas that may (if lucky) be technically competent, but probably need touching up to make them look good. I always appreciate someone with a good eye for the aesthetics, and in this case they'd also be technically familiar with what ought to be possible, too.