Passenger capacity, for example, on WCML (or ECML, MML) could be increased by increasing platform lengths (expensive - but a lot cheaper than a new HS2). Make all long distance WCML passenger trains 12 x 26 metres, with only 2 coaches for first class, and you would vastly increase the amount of standard class seating - instantly easing most overcrowding problems.
Increase all the (current LM) semi-fast & slow services to 12 coach formations (at least as far north as Northampton) and 8 coaches to Rugby & beyond - again a big increase in seating capacity
Ideally, but 12x20m is already the case on the busiest services - we need a way to provide extra capacity on these trains.
What everyone decries is the idea of Manchester/Birmingham/Leeds as London commuter belt
I'd have no problem with Sheffield being part of the London commuter belt.
At the moment, we produce thousands of intelligent graduates each year at two well regarded Universities - but if they want to do the jobs commensurate with such talents then they have to move to London.
I used to commute to Leeds for better wages - making my daily commute three hours (rather than the one hour round trip I'd have had if I'd stayed working in Sheffield). HS2 will make suburban Sheffield - central London take an equivalent time to today's suburban Sheffield - central Leeds commute.
So, instead of losing talented graduates to Big Bad London, we could keep them living up here, paying their council tax here, doing their weekly shop here, contributing to the local economy (buying their lunch in London, sure, but the bulk of their spend would be in Sheffield). That would then make it easier for companies to locate in Sheffield, given the talented labour market.
If we can use fast trains to tap in to the growing London economy then that'd be great.
The alternative is to keep waving goodbye to all that talent, knowing that they won't set foot in Sheffield again once they've graduated.
I cannot accept the case for HS2, I just can't. And knowing that, I have to be careful about just replying "nope no no"
So there's no point in debating with you because you can't possibly change your mind?
Okay.
I'm prepared to change my mind if someone can suggest something better (I was against HS2 a few years ago, but learned more about it).
If someone can come up with something practical (other than a vague "make the timetables better to find magic spare capacity on the existing network") then I'll listen. Convince me.
On the actual subject, my chief concerns about HS1 and 2 (in all its phases) is the number of spurs to termini. St Pancras, Euston, Brum, Manchester, Leeds are all dead ends
One route into a city centre will cost megabucks.
Two routes into a city centre will cost more than double that (since your first line can be a cheap/ simple alignment, but the second route will have to be pretty much directly opposite the first one (given the need for 400m trains to run in fairly straight lines - no tight curves, given the speeds etc).
e.g. Manchester Airport to Piccadilly is one thing, but extending through central Manchester to rejoin the WCML somewhere north of the city is going to cost a lot lot more.
So the "dead ends" make sense to me.