Even after april 09 (big pension day) NATS will still offer the best terms and conditions/pay in the UK, I agree with MMM that anyone who thinks otherwise is deluded.
I work at a UK regional airport and I earn less than I would at a comparable post within NATS, but I live in a very nice area, have a very nice house and standard of living, it's only a 20 minute hassle free journey to work and I thoroughly enjoy the job.
I could easily get a job with NATS, but I'd probably have to move or face a lengthy commute, in theory not have a choice where I worked, face a devaluation in standard of living and general lifestyle, consequently, I ain't going anywhere. the majority of non NATS atco's are probably in the same boat.
It's often been said that if ATCOs had nothing to moan about, they'd moan about it and that applies to the NATS whingers far more than any whinging ATCOs outwith NATS, largely because they know they're on to a far better thing than will ever be available outside the organisation.