Personally, I usually find Chiltern reasonably pleasant to travel with, but only so long as you are willing to move down the train to get seats, don’t mind the odd surge of popularity and so on.
Sometimes they definitely seem to be victims of their own success, though. This especially applies with the capacity on the south end of their mainline, the length of unit formations available for them to use, their generally reliable service meaning they don’t have as much experience managing disruption (which can really show), and more besides.
Perhaps mostly as a result of this, they definitely don’t have the capacity to take on the passengers displaced by the WCML and XC routes when they suffer failures. It would be lovely if more trains could simply divert down the Chiltern route, rather than simply diverting the passengers without providing the big metal boxes to stuff them into, but it’s just not that easy without a lot of costly contingency arrangements which would possibly be quite slow to implement in an emergency. Perhaps, with due apologies to companies like VTWC, Chiltern should feel compelled to decline ticket acceptance except in the event of seriously protracted WCML problems, simply because they will overstretch their own routes by allowing more and more crowds of people onto them. If anything, aside from the trains themselves, one day it will probably become more than even fairly large stations like Marylebone can handle. I already worry about how many people try to squeeze through that gateline at times, and it’s not like there is spare width of the station buildings that could be better used to make life easier.
Of all their rolling stock, I tend to think the Mk3s are certainly no more pleasant to travel on than the 168 units. The only benefit from a purely passenger-orientated point of view now seems to be from the fact that the Mk3 consists are of a length which is now really the minimum necessary, and you can also walk all the way through a Mk3 set to find a seat. (On an off-topic note, but by extension, I do understand it’s nice to have a powerful locomotive-hauled train from a novelty and enthusiast perspective, but compared to the relatively modern Clubmans, the Mk3 interior tends to look quite dated outside of the GWR refurbs, even with decent fittings, and the soundproofing on the Chiltern ones can be atrocious - you don’t have to be especially unlucky to find you can hear the hand driers and squeaks from the doors / gangways through the whole coach. Things like this, and the lack of catering for some, can start to be annoying niggles for passengers, to the point where it’s seen as no better than anything else.)
