VisionFive 2 and Star64 launched earlier this year with the same SOC and there's at least 1 board with more horsepower already, so I wouldn't exactly call it "flagship" unless you somehow really needed something else with the CM4 form factor.

Feel like because both the VF2 and Star64 boards have been out already out for quite a while now, with probably some of their teething issues sorted out, this is pretty much an inexcusable product launch for Milk-V. Even more so since the VisionFive2 copied the RPi format almost exactly.

And yes, a lot of repositories for these boards are very fresh, forcing you to compile stuff and will break your board if you update. There's some stuff like device trees and patches being upstreamed, but there's also a whole bunch more that's not being upstreamed, like GPU drivers.