Pros
A once-in-a-lifetime project to get involved in, with lots of like-minded individuals who are trying to build the best railway possible. An interesting challenge for civil engineering and railway folks to take on, with a wide variety of work and areas (civils, stations and rail systems) to work on. Salaries are quite competitive and work/life balance is very good (3 days in the office under a hybrid working policy).
Kontras
Due to the constant political and public scrutiny, the programme is constantly evolving, so HS2 is not a place that stands still. Bureaucracy can be challenging. Re-orgs happen on average once a year so if you're not comfortable with change, this may not be the place for you. The benefits package is okay but lacks those enjoyed by the civil service, while perks (such as bonuses, office niceties, offsite events) are non-existent as a result of being in the public sector. You even have to fund your own team Christmas dinner!