Just to pick up on a couple of things.

5338 doesn't have headrests. I would have thought the refurb would have been the ideal opportunity to get it sorted, rather than cover the existing seats.
Granted it's a little older than the native examples, but surely a standard spec would go down well?
It goes like a stink, but the glitch with interior lighting was noticeable. The offside lighting kept switching itself off.

One of the new 21's had issues in Eldon Square earlier, with passengers transferred to one behind. The one behind was a Chester run, so it left a gap of an hour for those wanting to get to Durham.
I believe it/or another dropped in at Durham to return to Newcastle.

On a B5 hybrid tonight and the damp patch/condensation on the upper saloon roof was pretty minging. Apart from the discolouring, I can't imagine getting 'dropped' on is too pleasant.
I would hope an internal inspection uncovers the issue.