Holders of Rail cards will be pleased to know that their rail cards can now be used on the cheapest fares on FGW. I am uncertain if other train companies will follow suit (or might be doing so already).
From email :
Get an extra 34% off* with the trump card for smart travellers.
Firstminutefares are now even cheaper when you book with a Railcard and bag yourself an extra 34% off* our great value advance prices