For a start, you just hit on my pet peeve. People that don't use the correct directory structure in their zips. It unzips everything to an ns_postpileb1 directory first, meaning i've got to bother to manually put everything where it should be. Please correct this, it is a massive irritation.
The .res file should be in the maps directory along with the .bsp, i believe, as should the ns_postpileb1.txt.
Ok, that's the problems before i load the map, let's take a look at the map itself now.....

First up, this door inside the alien hive room clips into the brush above disgustingly when opened, and even when closed it's still clipping into the brush about 16 units or so. This is the only instance of this i've found.

Here we can see not only the excessively poor rock formations, but also 5000 e_polys. You'll also notice the "50 fps" and "41.4 fps" readings from r_speeds and net_graph, this is, well, unacceptable. This is a 1.5ghz radeon 9600 machine i'm using, i shouldn't be getting such low fps from a map as devoid of detail as this one.

The water in the central room clips into the embankment at the side constantly, this may not be quite so distracting if it wasn't moving, but it is moving.

Is that supposed to be a button?

The minimap is entirely FUBAR, please can you check this kind of thing before releasing. Yes, i know this is a beta, but getting your minimap correct is literally no work whatsoever.

This door, leading to the central area has a gap on the side, it may only be about 8 units, but it's still very noticeable.

The map in general is pretty good on r_speeds but in this area i managed to get 1300 w_polys, this does cause noticeable lag.

The textures you've used on the connecting poles in the central area are stretched to a state of abnoxious ugliness. Can you
please take the time to texture, scale and align properly when mapping.
Well, all in all, this map needs a hell of a lot of work. It lacks detail over the entire map, the rooms are way too big, the res is unbalanced, the layout is entirely linear, the texturing is sub-par, the rocks are extremely unnatural, the readyroom is extremely poor and the lighting is forgettable at best. I appreciate that this is a beta and is not the finished product, but you have an excessive amount of work to do to make the map look less amateurish and nice to look at. Personally, i wouldn't have released such an early, buggy and unfinished release, i would have at least gone through to check for such schoolboy errors before even thinking of letting other people see it.