Pay is good, pension terrible. Expect £15K on top of PPJN basic after allowances. Gatwick is stress free, I doubt that Heathrow can say the same. Five nights away per month, limited destinations Gatwick, lots Heathrow (shorthaul).
Pleasant crew but don't expect a party atmosphere. Work levels are probably at or above EasyJet and close to Ryanair.
If you're below 30 go for it. Over 30 there are pro's and con's to consider due seniority.