Days Out 2 for 1 Heathrow Ticket?
 

When I take the train (not Express) from Heathrow to London (Bayswater), can I use my paper ticket for the Days Out 2 for 1 deal?

No. The HEX & HEC don't count for the 2-4-1 offers. When you get off at Paddington you can buy a Travelcard at the booking office at the platform level which will be eligible for the offers - and you need that to get around London anyway

What's the least painful way to get an Oyster card at Heathrow?

Walk to the booking office and ask for one. Works every time. As far as I'm aware, there's no painful alternative, though no doubt someone might create one for you.

But why do you want one? You can't use it on the HEX, and you can't get 2 4 1s with it.

Strange , I used my HEX tickets and got the 2 41"s!!

avalon -- which site(s) honored the 2for1 offer w/ a HEX ticket.

HEX definitely doesn't qualify (the website even says so - or used to. I haven't checked lately). My guess is the ticket seller simply saw a train ticket and assumed it was OK.

curious . . .