I'm going to sound like a cunt, but so be it. Forget my name is in green for a second, as I do not speak on behalf of the beta testing team but on my own personal behalf and no one pushed me to write this post but myself. No one but me is involved in this post. I do not represent the team.
The problem is not our ISP's, the problem is the fact that all your maps are well over 100 megabytes large.
That is exceedingly large for Source maps. Most huge Garry's Mod RP maps are about 120 Megabytes, and they are all laggy for a reason.
Your Duke Nukem map and music that comes along with it is over 800 Megabytes, despite the fact that this map is smaller than Basement classic in scale, and has textures that are 32 pixels by 32 in size
800 Megabytes is 100 more Megabytes than the entirety of the 2000 video game Deus Ex. It is twice the size of Half-Life 1. It is the same size as a Playstation 1 RPG disc. It is absolutely unreasonable.
My ISP is perfectly fine, I download at a speed of 12 Megabytes per second. The problem does not lie within our ISPs, it lies within your absolutely ridiculous overuse of assets that shouldn't be there in the first place, boosting the filesize of your maps to insane proportions that are extremely hard to handle by the Source engine, not to mention that most of, if not all of those maps are all unfit or unoptimized for multiplayer play. Logging into your server when large maps are on literally crashes the game.
I sincerely hope this post opens your eyes. (It probably won't, since you've got over 5000 hours in Source SDK and you do not seem to have any intentions of getting better at using the software in a fashion that makes sense.)
You can hate me all you want, bash me to all your friends, send backlash my way, it doesn't matter.
Just leave the team out of this, they had nothing to do with it. I made this post alone