I found that the article by Roger Ford was far more interesting: "Time to revisit the need for speed".
HS2 appears to be a "silver bullet" solving all sorts of problems in the railway network. The far more pragmatic issues raised by Roger Ford seem to address these network wide issues in a much more practical form because the ideas can be applied anywhere. HS2 provides it's improvements in a very limited number of scenarios and whilst it has very sexy speed improvements, taking a more holistic view of the time taken for people to travel from A to B is probably more important in determining whether people will change their mode of transport, or to generate an impact on the local economy.
I always wonder if the amazing reductions in journey times to/from York via HS2 are purely so that those with expensive homes in the pleasant Yorkshire countryside can get to and from work in London so much quicker. I don't see how this helps regenerate, or benefits, the North. Please explain. In my opinion, quicker travel between Northern cities and towns is much more likely to achieve a benefit for the North. Places that are currently well outside an even moderate speed rail network can be drawn into the new services.
Replying to the speed point, Mr Ford is of course correct, but that is not how the COBA calculation works. The benefit of any transport initiative is measured almost exclusively in time savings but note, only for the stretch in question. The time savings are graded in value. Someone travelling on firms business delivers a far greater financial benefit of time saved than a person travelling for leisure or social reasons. IIRC, commuting is worth more than the latter too. Savings in collision costs are also calculated, but these are a particle of the time savings. A fatality costs over £1m, a serious injury £60,000 and a 'slight' one a couple of thou. As these are rare events generally, that part of the benefit will not be decisive.
Then of course we have the 'wider economic benefits'. These did not exist when I was involved with all this (about 1993) so i am not knowledgeable about that black art.
What the anti HS2 people are trying to say now is that COBA is wrong and that these highly valuable firms business travellers can work at their computers so the time savings are less valuable than they used to be.
Going back to Mr Ford's 'holistic' approach, he does point out that if you are driving, you cannot be working on your computer, so if the comparison is between car and train, HS2 will be attractive, regardless of time taken. However that is not how COBA at present (AFAIK) works. The comparison is between (say) departing from Euston on a Pendolino and alighting at Piccadilly and the same trip on HS2. The time saved is what will give the benefit to HS2 and how you get to Euston and how you end your journey from Piccadilly is irrelevant.
These arguments are old friends of mine. when I was fighting road schemes in the 90s, we used to be able to prove that a bypass would merely shove the rush hour queue further down the road, but COBA takes no cognisance of such argument. Just that stretch was relevant.
As I say, I am OOD on all this but hopefully my points are food for thought.
My attitude is that if it is patently necessary that we need new lines, for goodness sake get on with their construction. The motorway traffic we see now has to come off them, as otherwise we will not fulfill our environmental duty to our grandchildren. Now, how big a railway do you need for that!!!