As for GhostHouse, I don't see to many cheaters. For the most part it's the same old crowd that visits there on a daily bases. I don't know what other servers are like but from what I've read on forums here and there I don't hear much. TKK use to get tons of cheaters coming to it back in the day. It seems to me that most of the cheaters have moved on. 

I don't think UT99 is dead or will ever totally die anytime soon, but lets face it the numbers are down which is likely why the cheaters are also down. There is not very many Freestyle type clans that are active anymore on this side of the planet anyway. From what I have seen, EURO is still has a strong UT99 communitty. FN most popular game is still UT99 but this is mostly on the camping side. 

UT3 is a cool game, it is nothing like Sniping UT99 that I'm use to but it's still fun never the less. I'm not sure how into it I'll get but I'm willing to give it a try.