This is very true! On android phones you can almost always run the latest version, but it's always a 3rd party distribution put together by... Who knows? And even the larger ones that are legit, like cyanogen mod, don't always work as well as you'd expect because of things like using a baseband driver that came with the oem 4.2 rom in android 4.4, and then using the camera driver from 4.1 because samsungs goofy code doesn't work in 4.4 unless you have the Verizon note 2 and if you have that one, you can't use cyanogen mod but there's a miui hack job made by this dude named toiApplesuxxor927482 that works awesome! Unless you use 64gb micro sd, in which case your phone will crash every time you open gmail after going to google on chrome.
Ok none of that is exactly true, but I think it fairly reflects my experience with a note 2 lol