Actually, there's some pretty nice stuff being made.
One of them, Elefants UMP Map Pack, has already been shown a bit and I've played them. The gameplay on the maps is nice, one of my favorite is probably Chamber. Still a bit to fix, like all the black marks from where shots hit...but otherwise it was kind of neat.
I've seen/helped/played with some other stuff as well, and trust me, they aren't horrible or just "random shit shoved into a terrible map." Keep in mind a lot of the members are (on average) between 10-15 or so, making the content just a bit more impressive.
So please, at least give the maps a try when they are available for download. Don't just shove them away if they're shown terribly by CE3.
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