Doom map Double Impact style

I love the style of DoubleImpact WAD, in the mood of early DOOM1 KneeDeep episode (one of the best Romero efforts). Maps are detailled enough and beautifully crafted, textures are perfectly aligned, sector height adapted to the textures, and so on; resulting in the classic Episode1 ambiance I love so much.

I should make maps by noting what I like, in an explicit way : textures set for walls and flats.