FDAs for 16 to 20.
Map16 - kind of an odd start, having a SG with a bunch of monsters around and no other weapons in sight. Taking them down would clearly take too long, leaving them alive makes exploring annoying. Anyway, running into that unclosed sector made me wonder if there was an updated version available, and I was bored already, so closed the game; not feeling like giving this map another go.
Map17 - started well with that outdoor area, went bad fast. It's a depressingly easy and repetitive slug; then near the end it turns into arch-vile spam on every fight, without appropriate ammo.
Map18 - I tend to hate city maps so ran around for 30 seconds and closed the game.
Map19 - entertaining, yet bordering on bullshit most of the time. Start is ridiculous, almost pitch black area with monsters heading towards you right away and you're supposed to turn around and take a shot at a switch? Come on now. Cybies mine fight was fun, but the arch-vile detracted from the whole thing. Cybie trap later on is silly hard. After running around for a while, with 2 monsters left and not finding a way to activate the exit, rocket launcher to the rescue!
Map20 - in space, nobody hears you bump into cramped architecture. Or so I thought until I reached the outdoor area. Way to shortsell your map with that start. :)
Great atmosphere, this can't be overstated. Gameplay is for the most part passable, giving you something to do while you ooh and aah at the environment, and that's okay, the visuals alone are more than enough to carry the map.
One issue I had though is there's only enough health to play very conservatively, and some traps are downrignt unfair on a first playthrough *and* become trivial after that (revs at yellow key, chaingunners/imps after teleporting). Hence I ultimately gave up, but will definitely replay this with saves. Nice one.
Lots of wall detailing here and there without impassable lines.
Speaking as the author, I definitely don't want the SSG moved. It's where it is quite deliberately, and I doubt any reasonably thorough Doomer is going to miss it.
As far as ammo/health goes, if there's a consensus in the public beta that these are in too short supply, then adding more is no big drama. I'm not sure that consensus will appear, though. Certainly none of the CC4 playtest group reported a problem, and the tcount stats indicate there's plenty of both.
"It's not that bad" and its variants never strike me as a convincing argument. Naming an automated program when talking about balance is downright worrying.
Explaining what is the point of having the SSG there, why is it important for it to be there rather than someplace else, how does it all fit in the flow of the map, and likewise with the ammo placement, would be much more interesting in my opinion.
Of course, you don't have to justify yourself to me. You certainly don't; but I just feel that, personally, if I can't describe any design choice I make based on what positive effect it has, it's probably a bad decision, or at the very least superfluous, and experience often confirms that notion. YMMV.