Isn't the 1552 the service to Worcester? Last few times I've caught it to go to Kingham it's not advertised as calling at Reading - though it does stop to pick up only and seems to take a long time to do it.
Time to get back to the old fast expresses? Ah, a bout of nostalgia beckons.
Once the work is completed at Reading the plan is to have some services run non-stop through Reading. The linespeed is to be raised to something like 100mph on down main platform, potentially higher once (or if)
ERTMS▸ is up and running.