Just tested it, I couldn't get a full experience since this isn't waypointed, but I got enough to give constructive criticism.
Since this is a very large map, M79 boosting or minigun surfing shouldn't be a worry since how long this map is and how long your jets last. The farthest I got was the islands between the one with the flags and the middle with the pole. Spraying I think you did a nice job with keeping to a minimal. I should point out that the pole is made from very thin polygons, sometimes in servers where lag is taking place, bullets from Barrettes can potentially penetrate it. Adding colliders would completely remove this factor. Also, I think many players wouldn't use the lower routes, since how straight forward it is through the top route and how based on how long it takes to go through the bottom one. Its about a 1 to 3 ratio. The lowest route can have some major camping problems. It has no scenery or protection and the terrain is fairly flat. Add something like crates.
I did experience some issues referring to FPS. I think you could remove about 200 or so polygons like in the islands or around the border. If you do so, it can really make a difference in performance. For the island with the flags and where you spawn, it can easily be sliced in half. Since you can't access it and it serves no use besides looking nice, I recommend you remove it. If you do, don't add scenery to add effects, just completely cut it off. Since you can't see it, it doesn't need to be enhanced.
For positive things, I really like the visuals though. The best thing I would say is probably the lighting effects between the islands. The multi-texturing is also quite nicely done. It could slightly use some more stretching, but it isn't necessary.
Overall, its a really good map and based on the maps I've seen you make, I'd say this is your best work.
