Is Heathrow Connect or Heathrow Express a part of the National Rail System? And if so, would it make sense to book a round trip from Heathrow to London (we're landing Christmas Day)? Could we then use the 2 for 1 coupons to London attractions and purchase an Oyster card instead of a London Travelcard? I've attached the statement from the Days OUt Guide website. How do you interpret it?
"If for example you buy Return tickets to London, outbound on a Monday and returning on a Friday, you will be able to use the vouchers throughout the Monday-Friday period, provided you show both outward and return portions of your tickets (remember to tell the train company staffs that you need to keep your outward tickets!).
If for example you are buying single tickets, e.g.Advance tickets to London for a one-way journey on a Monday, and Advance tickets for departing London on a Friday you will be able to use the vouchers during the Monday-Friday period, provided you show both outward and return tickets (remember to tell the train company staffs that you need to keep your outward tickets!)."
I've tried unsuccessfully to contact the National Rail and Days Out Guide. Can someone shed some light?