The perils of an internet forum I guess.
It feels like every day there is a story which means that 1 of the 4 diagrams will not run as planned. Whether it is because a set needs an exam, there is insufficient storage capacity at Crewe, or simply that there is something out of position from the previous day.
I used the 16:30 from Manchester a couple of times in the past few months and it was a MK4 as planned. So that is a 100% statistic from my actual experience.
There is far, far less of the pre-planned swaps than before now and far more being put into getting things into place than would previously have been the case, with units swapping in and running ecs to pick up diagrams etc which would at one time not have happened.
I think some of the opinion is probably my fault for saying it! In reality for example 1588xx or 1971xx may be out of service due to an exam/waiting parts/fault etc etc and a service gets run as a 2 car vs 3 or 4 or is cancelled altogether, 197 late off depot due to exam requirements/faults and turns round at Manchester Picc rather than Manchester Airport. These things aren't really mentioned and so slide under the radar and nobody notices but they're all almost daily occurrences.
When 4 diagrams are planned and do run, which is often now several days at a time nobody, including me, says anything buy it's certainly happening more often than not now as those figures show. Personally, I'd be suprised if 197s figures of running booked lengths etc was as good.
After saying all that though, HD02 had another issue and hasnt left for the first Crewe to Cardiff. Both HD02 and 07 should be ready for later so all being well one of them should be able to swap into the diagram later.