Hi
I worked at LGW for AA for three years and I think they are a great company. I was on check-in then went onto being an International Departure Co-ordinator. At Gatwick they only took us on as part time but I was on excellent money. You get premiums if you start before 7am, work on a sat and sun and also you are paid for 13months of the year so every apr and Oct you get one and a half times your monthly pay. I was sent over to Dallas twice on courses, travelled first class each way both times.
My only gripe is that the lead agents I worked with were a bunch of B*****s, hated their job because there was no promotion available but wouldn't leave because the money is too good and the concessions are excellent. Put it this way, i went home to Oz every year and only cost me £180 return..... I do not know what the staff are like at LHR, but go for it, they are a great company to work for!!
Good luck
GFW