You're being
way too hard on yourself. People see new models and something different and then they hype it up to be the best map ever. They're bound to be disappointed because they set their expectations so dang high that it's difficult to fulfill them.
I actually enjoyed the map. It has a lot of potential, though I admit that it could use some work. Here's some suggestions on how to improve it.
-One thing I liked about Astute's Kamino map was that the units had jetpacks to help them get across the map faster. I think jetpacks would really add a lot to your map and solve the distance problem that people are complaining about. Personally, I didn't think the distance was that bad because, as you said, the long range weapons even that out. However it can take some time to get to a CP to take it so this is why I highly recommend the jetpacks. For the droids you could simply allow them to jump higher and farther than normal.
-I was thinking about how you could incorporate vehicles into the map without having to model something brand new so I came up with a few ideas. I'm not sure if this is possible, but you could try turning the BARC speeder into a flyer by using the model and then alter the speed to make it seem like an underwater vehicle. Same goes for the STAP. For the CIS, you could give them Spider Droids (apparently those work underwater) and Dwarf Spider Droids. This would make the rocket troopers more useful. You could give the Republic a lot of those bikes to balance things out or give the clone rocket trooper improved weapons.
-Ask Astute if he has his health and ammo rechargers from his Kamino map. It sucks when you run out of ammo and don't have anything to use against the enemy.
-Some lights would be nice because it's hard to see in some areas and I think it'd really add to the ambience.
-Some well-placed auto turrets may make the map more challenging and require players to use team work and strategy, assuming that this map is designed for MP. It'd also make the map seem more action-packed.
-You've probably already thought about this but perhaps you should give Kit Fisto the Emperor's animations so that he's floating. It's a little wierd seeing him running at a normal pace while all the other troops are moving a lot slower. I don't remember if I tried jumping as Kit but it'd be cool if he could float for a while like the Emperor or Vader.
-The quarrens would be cooler if they had Vader's "jump" animation and could float in the air for a period of time, just to add a bit of realism to the map.
-The map is a little simplistic, I think it could use a lot more detail. I'd add boulders, rocks, foilage (or some sort of sea-plants), crates, retextured Bespin tanks, and perhaps retexture the Geonosis spires and add'm in there too. Whatever fits and makes the map more elaborate.
Anyway those are my ideas/suggestions. Some are kinda preposterous so I wouldn't really expect anyone to go through with them. I probably wouldn't.

They're just food for thought. Good luck, and good work!