Sorry - I sometimes abbreviate too much.

The HEX is the Heathrow Express. The train that goes Paddington to/from Heathrow.

Just another voice to say that if you want to stay near Heathrow for the night, we've gotten great rates on Heathrow airport hotels using Priceline (name your own price).

If you really want to see London and can spring for the transportation back and forth (either Gatwick Express and Heathrow Express, or car from www.justairports.com), I think you could spend a nice evening in the city. It just depends whether you want the hassle of going back and forth to the city, or if you'd rather just get to an airport hotel at Heathrow and relax for the evening.

janisj,

Thanks for correcting me about the District line. I know better, but my brain slipped a gear or two!