I am trying to explain my point hence my reply to you and post. I have never said Scotrail's other fleets do not have issues. Why do you suggest that.
One distinction I would make though is that the other fleets are just that - a fleet. Wabtec have been unable to provide a fleet to date and probably never will. I asked further up how many sets are now with Wabtec for refurb. No one knows I guess but it's not looking good. The fleet as planned does not exist.
I'd also ask how many other fleets have been delivered to about 25% of total vehicles promised and of that 25%, what other fleet shows the level of failure to carry out diagrams? I am not suggesting Scotrail's maintenance is great. Clearly it isn't but we can't ignore the facts.
I know it's easy for me as no I longer live in the UK and no longer travel on Scotland's railways regularly like you obviously do, and the delays and frustration must be very frustrating for regular users on the HML. As has been pointed out elsewhere though, had they gone with new stock, based on the issues and delays we've seen with the Mk5's, IETs, Class 385's, Stadlers etc. we would likely be in the same boat. I'm not sure why we have the issues commissioning new stock in this country, but every new train brought in seems to be beset by teething problems for many months after they are introduced. I know it's very easy for me to say this watching this saga from afar but given more time this can be turned around. The HST is still running well elsewhere and as more sets are delivered it can still be a success in Scotland as well. Journalists and the public have remarked on how the refurbs are a step up from previous stock; we just need to get more of them finished and running. Now that the castle and XC conversions are drawing to a close, that should help the rate of production.
Something really smells off with the way the HST introduction has gone in Scotland though. The power car traction motor issues aside, it does smack me as very odd that the refurbished castle and XC HST introduction programs seem to be going well and LNER/MML can keep their trains going effectively but ScotRail is struggling so badly. The core of the power cars (the MTU engines) are 10-15 years old. I just wonder if organizational issues are contributing to this. From articles I see like the one posted by the BBC yesterday on the retention toilet delays, the relationship between the managers and the train and maintenance crews seems to be very much "us versus them" on both sides. I also saw some very colourful comments from Mike Cash on the HSTs when there was an incident with an engine smoking at Queen St a few months back. I can't comment on why the culture is off or who/what is driving it (management, unions or a combination of both), but with a toxic environment like that definitely doesn't help, and it wouldn't matter what new stock we had running on the railway (NOVA Mk5, IET, Voyagers); there would still be a major struggle keeping things running if the management and unions can't work together to address the operational issues.