I've claimed Delay Repay only once, when NR shut the WCML at Motherwell with signalling problems, so that meant a Glasgow-Carlisle bus on the A74 and a 2-hour delay going south on Virgin.
I've also claimed once abroad, when the Austrian Westbahn had a power failure for the best part of 3 hours, leaving our ICE stranded in the sunflower fields.
I was impressed when the DB conductor came round afterwards with already-stamped claim forms for "over 2 hours delay" (50% rebate).
Looking back, I reflect on the many, many times BR dislocated my journeys without a shred of regret or compensation, especially on Sundays.
But on the other hand they did more special stops and coordinated their recovery services better than today's TOCs (alternate routes, connections etc).
I still have "has been delayed on the xxxx Region" on the brain (substitute BR Region to taste, usually Western or LM depending where you were).