This is a well done design with a really clean look. I've had a few matches on here and my issue is the whole map feeling scaled too big. Rooms felt to large and open and movement and player descisions suffered from this. The rooms lacked the depth the space indicated. Just too slow paced for my taste, but I really like the design.
I'm not surprised you feel that way, to be honest. All my maps tend to lack profound complexity in favor for better room-to-room conflict. My maps are basically one convoluted room stretched out to fit a regular sized map; each encounter takes place in the whole map rather than just one of its rooms.Of course this type of map isn't for everyone, it's mainly tailored made for me and my friends who have a very irritating play style, especially concerning tunnels.
Designing 1v1 maps to fit a particular playstyle can be a good thing, especially if you're playing the map with other people that play similarly. My experience on the map was apparently different than those already mentioned. I actually felt the gameplay was too focused around the upper catwalk, and that the exterior portions of the map were underutilized (not due to being oversized, but due to a lack of incentive to move there). Your weapon and powerup placements are interesting to me, just because they are so contrary to what I would personally do. I'm kind of curious to see how the map would play if the power items were moved to the exterior rooms instead of the tunnels and catwalk... If it works well as is with the people you play with, though, I wouldn't really suggest changing anything.
I have a slightly different take. When I played this map I simply used almost nothing but the outside and only went top when os was coming up I used side room open to the catwalk and shot the **** out of them and would come up the backramp unless I spawned near portal or dropped just to hit the portal. I also would fake lift and always push bottom middle and take advantage of the glass catwalk and position myself to make it hard to shoot and would grab plasma pistol sit tunnel for a second and pushed the necessary direction. When I played people that pushed top the whole time I 15-3'd so... The map flows through the top but the power comes from the bottom. That being said, my issue just cam with the on far side of big room not being used no one really ever jumping up from catwalk room. I think that is the biggest reason it feels top heavy is because everyone just hits tele from bottom catwalk room and people just tend to think that because the map puts them at the top all the time doesn't mean it was the best position on the map.