As a (former) Thames Valley commuter I was going to say Delay repay seemed a bit of a retrograde step. But it seems a railway with no passengers is much more reliable - for the first time in at least the last 5 years there is no current season ticket discount for punctuality or reliability for the commuter services.
I would have agreed last year but as I didn't renew my season ticket I'm assuming I've lost my regular 10% discount so I guess delay/repay means I can claim something if I go back to regular commuting (which is looking unlikely).
It's probably the fairest way to transition to the new system as well as I suspect the number of people who lose their discount will be relatively low.