Now doubtless
sunrisegirl will be along shortly to defend her patch, but in the meantime I will do so too.
I confess to being slightly bemused by the LGW criticism, certainly the North Terminal. Yes, if there was a T5 at Gatters then trips through there would be a little better then but T5 is meant to be the best of British terminals. How does LGW North compare with the old T4, I wonder?
One of my main gripes / praises is that a decent rail service goes from both to central London, but at least LGW's rail service goes somewhere else! If you don't want to use the Piccadilly Line or get on a bus from LHR then you are going to Paddington - whether you like it or not. From LGW you can go towards the south coast, or change at Clapham Junction, or carry on to Victoria.
Perhaps I'm a little biased because I live in south London, about 45 minutes drive from both airports, and getting from my house to LHR by public transport is just ridiculous.
I do agree that the atmosphere at LGW is different during the school holidays, and that the airside shops are perhaps aimed at the lower end of the market (Kurt Geiger vs JJB Sports!). It would be nice if security allowed status pax through the business lines too, but then I've been stuck in 'FastTrack' queues at LHR longer than my average wait at LGW.
So I write in support of my most frequent airport, which has also noticeably improved lately. Unless, of course, the OP was talking about the South Terminal, which is full of dozy holidaymakers and as such makes going through there absolute hell!