Id Software deserves all the credit for starting the whole 3D action game genre. The following observations are not meant as a criticism of Id's Wolfenstein engine. They are only meant to illustrate the difference in features between the game engines. The Pie 3D engine can have wall sections at non-90 degree angles, short walls, and tall walls. DOOM, Like the Pie 3D engine, can have non-90 degree walls and so on.
All walls are the same resolution.
The Pie 3D engine can have solid, windowed or shaped walls, archways, fences, file cabinets. Anything you want to build out of vertical wall sections, tall or small, will work beautifully. You can use any practical resolution for your artwork, you aren't stuck with using 64x64 pixel images. DOOM also can have walls with cutouts or windows. The wall resolution appears to be fixed at 64x64 however.