I've had a look at the CTF map, mmctf4. Here's some suggestions and comments:
There a very long line of sight on the upper level, you should definetly try to block it:
This room would be more interesting if the ground wasn't flat. Maybe also add some details like a bit of shallow water or sth like that to make it look more interesting. The circle strafe to the statues to grab the health bubbles / shards seems too hard for what you get for it.
If you go through the tele and then back (through the tele at the target location), you are thrown at the wall to the left because the teledest is heading the wrong way. The JP on the left takes you too high (as stated above).
I don't like the RA/RL area shown here. No gameplay, tight, dark.
General thoughts:
* (texturing of) the lower level is a bit boring
* some hallways are a bit tight, especially the ones to PG with the windows you can look/shoot but not jump through
* the same hallways are a bit boring because they offer too little interaction with players in the central area - you can shoot at them through the windows, but it's rather pointless to do it from in there. I avoided these areas almost completely.
* JPs take you much to high up, making you a *very* easy target
* Don't know if you really need all of the teles.
* Too little interaction between the upper and lower level. Maybe force the player choosing the lower path to expose himself to the upper level in the central room.
I think the general layout isn't bad, but you should try to improve some of the things mentioned above, most of all the LOS and other gameplay issues. I like the flag room (though the stairs leading up to the flag could be a bit wider)!
Hope this helps you.
Keep it going!