Always happy to hold someone's map and talk to Thames / Heathrow for them! Ironically, the lanes are often easier at night - you just follow the blacked out bits! Watch out for LHR changing runways, this can lead to some routes being closed, and be aware that the Radar at LHR is very, very good...I had a very peeved navigator once after LHR told him he was 200 yds off the route...
Enjoy the view, stay alert and watch out for R22s coming the other way.