Nick,
With hindsight and experience:
I would have stayed where I was or gone to Virgin/Cathay.
I can't leave now because there isn't anything better after the time I have put in here........so far!
But, the only way you will know is to come yourself and have a good look around. Ask lots of questions (like why have half the recruiters resigned recently
) and talk to some of the guys outside the recruiting/assessment sphere.
Good luck