On your E1M4 shot, the only complaint I have is that the level looks a bit samey when compared with E1M2 now. The coloration is very similar. I was never a fan of how garrish the M4-M5 textures were before, but they did offer a good amount of contrast compared to the M2-M3 set. Now it looks like some of that has been lost. The map architecture itself is great now, though.
Greenlight just fails on so many levels. Even Valve has admitted they're not happy with it, but all they've done to improve it are tiny things when they probably just need to completely overhaul how it works. The biggest problem is that I bet the majority of Steam users don't even bother with it anymore - I know I've almost completely forgotten about it, and really only vote for a game when I see it mentioned elsewhere. So you're not getting votes and Steam isn't exposing your game to its users. Problem is, any way of solving that would just make Greenlight intrustive and ad-like to users who just don't care about it. It's really unfixable in its current state - relying on the general public of Steam users for this is the wrong thing to do, IMO. The old approval process was even worse, though, so I think they need to go with some sort of hybrid setup.
One thing I really dislike about Greenlight is the fact that unfinished games can be greenlit before finished games. One game I really want to see on Steam is already available on the DS and iOS, it's in the top 100 (or was, anyway), and it hasn't been greenlit yet. Why? Why are unfinished games (and I realize Wrack falls into this category now) allowed to take "slots" away from finalized games? I mean now at least they're letting people pay for alphas/betas, but before it was just "oh here's a game, maybe you'll get to buy it on Steam in a few months/years, provided the devs actually finish it."
I disagree with your bit about devaluing games. You have to factor in the cost of materials (Tetris came on a cartridge), packaging, retail space, etc. None of that applies to Steam, and it's complete BS that some publishers try to charge $60 (worse if you live in western Europe or Australia) for their games on Steam. It's outrageous markup considering they charge the same amount for console/PC retail versions, where they make considerably less on each sale. If you can make more money selling your game for $2 than $20, isn't that a good thing? It's not devaluing at all, it's just putting your game within the grasp of more players, players who would never buy it at $20 in the first place.