Having worked for an airline in the UK I do not agree that the salary at GF is better than a UK salary!! In the UK I was earning approx 1200-1300 GBP monthly afer tax. I haven't been flying with GF for very long but from my own experience and from talking to other crew it is unlikely that I will earn anywhere near that ammount with GF.
I know that everyone tells you not to complain because it is tax free and you get free accom but the salary does not compare well to that of other airlines. It also depends on where you are from as the exchange rate is not good against the pound so the Brits seem to get a bit of a rough deal!