I just got back from a trip where I used an 8-day BritRail pass. I was a bit disappointed that scanning it at ticket barriers almost never worked (but fortunately, there was usually a staff member right there to look at the pass and let me through), and I wish that I'd been able to add it to Apple Wallet (which would have been somewhat easier to deal with than having to keep the PDF file elsewhere on my phone).

One thing the British rail system has that I wish Amtrak would adopt is having digital train status displays at (just about) every station, even small ones with relatively limited service.