Given all the histrionic criticism of the 230s, I don’t have much sympathy for the lack of service.
What a nonsensical statement. The 230s were criticised because they were wheeled scrap. They have so many problems that they have during the period of their tenure utterly destroyed the service from day one of implementation (even my very first ride terminated at Ridgmont, though the nice gateline staff at BLY allowed me a free ride when I said I was going just to ride it and didn't know what ticket to buy as I didn't know how far it'd get).
I was in favour of them until they utterly destroyed the line's service. I still think it's a shame they didn't work, but the fact is they didn't, and TfW are now having problems with theirs as if to prove the point further (though they have more options to use other stock e.g. 197s or to PRM a few more 153s because they don't have platform constraints in the same way, and the Welsh Government is not as stingy as DfT with funding).
I get that you do like to support the railway's line on things, which is fair enough, but in this case the situation cannot be defended. It can only be hoped that the 150s bed in nicely and allow a period of consolidation and recovery for the line.
My biggest frustration, however, is not the reliability of the units per se but the loss of opportunity. The arrival of the 230's was a time of promise, the trains offered a much nicer passenger environment than the 150/153 they replaced, had much better facilities and were much more accessible. Passenger numbers were climbing ( despite what the official figures might show) and goodwill was at the highest I have ever seen it, PR was fantastic and people had even stopped laughing when you said used that line to get to work!
This of course was a flaw in the 230s on its own. The doors were (and are on TfW's units) so slow that the only viable way to work them was from the back cab which has a narrower door that opens and closes more quickly. The outcome of that was that it was effectively a free service unless going to/from Bedford (the gates at Bletchley are not in use that often). TVMs were installed as a part-mitigation but most people didn't use them on the basis that they would get away with it because staff have long treated it as a "Paytrain" (using that actual term on occasions), and also because they are only on one side of the level crossing so people were reluctant to risk getting stuck by the barriers coming down.
With the line not interacting with much bar a bit of freight and long layovers I'm not entirely sure why they never just added 5 minutes to the running times, but it's been a problem throughout.