As it's new build, anything structural is covered by the NHBC guarantee for 10 years. You also get a £500 annual allowance each year for 10 years for essential maintenance. This can rollover once, so if you haven't used it the year before, you get £1,000.00.
Our hot water cylinder has a 25 year guarantee, as long as you have it serviced annually.
When some tiles slipped in gale force wind, the HA came and fixed it on the second working day after reporting it. It wasn't for us to do.
We like having a S/O house, and we certainly couldn't have afforded a house this big / nice without the scheme (the location is amazing too).
The new S/O scheme also has 995 year leases, not 125, like the old scheme.
Make sure you get a brand new, not a sell-on, S/O if you go for it, to make sure you get the maintenance fund and long lease benefits.