Hey! I like how the map develops. Maybe I missed something, but do you have a download for the new beta? I'd love to check it out. I had a run through b1, and I have to say: I love the layout.
Here are some more thoughts:
First, I'd be careful with the lighting. Not just from an aesthetical standpoint, I think you got this quite well now. I'm talking about "dark spots". As a rule of thumb (and I had to learn this the hard way), everyone's monitor is about 3 times as dark as yours. Actually, it's a good idea to literally turn down your monitor to the darkest setting for some test runs. It's partly for technical reasons, partly a psychological thing: People don't care about lighting when playing, so, if they ever feel like a lack of lighting contrast made it difficult for them to see some player in a corner, it's the map's fault. And they'll hate you for it.
It seems overdone at first, but I found that gameplay-wise, the best way to light a map is to have
seamless light sources for literally every square inch of the map. That means lights should
overlap and there should never be any "true" shadow, no gap between two lights. This often means one light for every wall/corner of the map. That includes walls that aren't lit directly but still look "bright enough". They usually aren't. Especially for outside areas. The sun is the best light source you could ask for, yes, but the parts that aren't directly lit by the sunlight, the shady parts, are already too dark and need an artificial light source, even outdoors. Those parts usually look especially dark because of the stark contrast.
Sometimes "silhouettes" (a dark spot between two brightly lit walls where you can make out players easily against the background) do work, but mostly just lighting the hell out of your map is the easier way of avoiding too dark areas.
In short: Add more lights, you won't regret it.
About item placement: I'm not religious about it and you'd better listen to people who play HL2DM more competitively than I do. But here are some things I noticed:
Medkits are extremely powerful, probably the most commonly needed item in the game. So place them consciously. Avoid placing them next to good weapons or ammo, so people have to leave their favorite spots in order to refill health.
Instead of placing 3 items of the same type next to each other (it's tempting sometimes), just put there one. No need to force-feed players.
Place a weapon and its ammo far from each other. Again: Make people run!
Remember, there are more physics items in this game than exploding barrels and crates.
Make powerful weapon placements compete with each other. Like the xbow being in clear sight of the RPG or a combine-ball. And vice versa.
Last but not least: Build cubemaps. I haven't heard a good reason yet not to have cubemaps, in even the crudest beta releases. Place an env_cubemap in the middle of every room or major corridor, compile the map, load it, set "sv_cheats 1", type "buildcubemaps" in console and reload the map ("map dm_technic_b2" etc). It's really easy. And if you don't do it, you get the overbright error/skybox reflections for everything instead, which looks terribly error-ish.
... wow, what a text-wall. Sorry, I'm hopelessly procrastinating atm and letting it out on forum posts, I hope you can read something useful out of it.
