The light shouldn't be too harsh at that time, especially if shot from the end of Cains Lane where they are very low (providing of course they are on 27L before 15:00). Also, AF
380s will soon be a novelty at LHR
and so an image from that spot with all the trademark Heathrow hangars, etc. in the back will be quite special. I'd sooner have a reasonable shot of it than nothing at all, however I also see the appeal in a shot of the Sun Country at STN
The light for the AF
380s would be better in August, if they are still planning to operate it until then? West-east aligned runways are always awkward at the height of summer but with care decent shots are still attainable.
I'll no doubt have a go at it while it's operating but I shan't be hanging around for the departure shot.....