I just competed 2 return legs from LGW.
BA counters - no rush, relaxed, very decent attitude,
Fast Track- perfect, I was the only one going through it.
General staff- very friendly
Unfortunatly very inconvenient to get too- despite living reasonably close to M25- for the two trips I had booked both times the Gatwick Express had major delays meaning I had to take a car service instead.
Even my driver commented that it shouldn't be called London Gatwixk as its a pain to get too.
Drop off is annoying and arrivals felt drab, miserable and quite slow.
I do prefer the e-passport gates here in LGW which are slightly different to the T5 ones.
Prefer LHR and while LGW has its many plus points it is inconvenient for me and just seems to lack a certain 'feel' to it - may sound weird but for me both T5 and T3 have a buzz and electricity to it that I am yet to get bored off