I think that the 180's are fine for the route, I.e. two more carriages than the turbos, and a speed increase down the GWML on the Reading stretch might help make up time when there are delays. However we do know they are unreliable so I guess that's nothing unexpected. But I can't think of any other available rolling stock to use, so they'll have to do!
When they get going, they're on fire...
...literally!