Protection is a pain when you have a team made up of people just going for points. I've noticed they'll just stand near the PKE Disruptor and draw all the ghosts towards it, making it much harder to keep it from being damaged.
I'm a big fan of Survival, though I'd love more waves (10 just doesn't seem long enough sometimes). After a few waves there are enough ghosts so that even the “point hogs” don't ruin it. There isn't that annoying ‘consta-slam’ thing going on, don't people realise that getting it into your own trap doesn't add any bonus.