Hey Krakah, didn't see this post until today. If you have any issues with UT3, let F3ar0n or I know. We've both struggled with them. Not to say other servers don't suck, but UT3 has got to be one of the worst servers I've ever dealt with.
One issue I haven't been able to get around is allowing steam-based UT3 clients to connect to a dedicated server without getting dropped. Typically they can connect on first startup of the server, but on a map change, most will get booted and can't rejoin. Only work-around is to leave UT3 running, alt-tab to windows, load up task manager and kill steam.exe, then alt-tab back into UT3 and you'll be able to connect fine.
I opened a ticket with Epic and Steam and they eventually came back saying it's a known issue and they'd post something if it's ever fixed. It never has been.