But the update experience on flagships (except if you count the Nexus 6P) is absolutely terrible. I had an Android excursion: Nexus 4 -> Moto X 2013 -> Moto X 2014. Motorola was known at the time for quick updates. This meant in practice that they pushed out an extremely buggy Android 5.0 quickly, and then waited half a year to push out a release with fixes. On the Moto X 2013 I had to wait more than a year (!) for Lollipop, although at the time of release the phone was only released a year ago.
tl;dr Android updates on non-Nexus flagships are terrible. Updates are typically months late and stop after 12 or 18 months.
> But the update experience on flagships (except if you count the Nexus 6P) is absolutely terrible.
I don't really agree. I have always got regular security updates on my Samsung flagship phones. Yeah I will have to wait ~6 months for Nougat but that's hardly of any concern. There is no feature in Nougat that I don't already have from Samsung. The only thing you have to care about is the monthly security patches and Samsung has been one of the fastest to issue those every month.
tl;dr Android updates on non-Nexus flagships are terrible. Updates are typically months late and stop after 12 or 18 months.