IMHO, all speed cameras distract drivers from actual driving and are therefore a bad thing.
After my second SP30 offence, I decided it was probably me at fault not 'the man' and so now observe speed limits. It's a pain in the arse and driving would be much more fun if I could drive as fast as I feel is safe but that's just not how it happens.
Now when I see a camera I can sail through whilst only checking my speed, rather than the half second of panic as I quickly check my speed, decide what the limit is and brake before hitting the stripy road.
Sorry for getting all sanctimonious!