Ok...
The main problem I have with your addition is that it's not particularly connected to the level. You've got one steeped ramp hallway in and out. The hallway itself is a gigantic death trap, and so you'll basically be in either one room or the other for an entire wave.
I'm editing the map right now, and I'm going to make some changes to it that I think would improve it. Feel free to keep or change or remove whatever you like.
Will update this post with a link here when I've done some stuff.
Update ...
Just tried rebuilding, and adding reachspecs was taking like 30 mins, and many player starts were outside of the level play area. Not entirely sure why reachspecs was taking that long, but I assume it's because of the invalidly placed pathnodes... Be a good thing to watch out for in the future.
In order to fix the reachspecs taking so long to build, I ended up deleting all of your playerstarts on the map, and also your adrenaline pickups (all pickups are also pathnodes, so it's usually not a good idea to place them too closely together)
I also found a lot of duplicated brushes -- In other words, you'd have a subtractive brush of dimensions 256x256x256 at position X... And when I would move that brush, I'd discover an identical brush in the exact same position as the one I just moved. This is usually a bad idea, so be on the look out for this in the future.
I also removed the signs you added from the play area -- I didn't care for them that much. If you still want them, though, I just moved them over to the side. Also, I embedded the textures into the map, so if you want to use them, use the versions in your MyLevel texture package, that way banner.utx won't need to be distributed separately.
Just a laundry list of things you should probably do before releasing this -
-First thing you should do if you use the map version I made is to save it as something different (ie, DM-CidandeB) so that there aren't version conflicts. It's usually a good idea to increment a version number or something on every public release of a map.
-Change the gametype (F6 - LevelInfo) to xGame.xDeathMatch. I would've done this, but forgot.
-Add in more playerstarts, and make sure they're in the subtracted level space.
-Add in a few pathnodes into the center area at least.
-Add in some adrenaline again. I felt like the amount you had in there was really excessive, but some is good
-I made some changes to the level, but it's only really "done" on one side, so if you like what I did, go ahead and copy it over to the other side.
-Some lights in the new areas would be good, I was pretty lazy with it
If you want to expand the level more (it's a bit small still) I'd suggest trying to add some side areas rather than trying to expand upwards. There are short little corridors that lead to stairs right now that you could probably extend out a tad and then add a whole nother room onto the end of.
DM-CidandeA