Windows UAC is the best I have used on any platform. What I can remember it was not that good on OSX. Not even Ubuntu gets this right. However the permission system on Windows is a hassle.
I always have a normal user account and an seperate admin account. The normal account does not have sudo permission. This setup on Ubuntu and what I can remember on OSX is not hassle free because a lot of installers and apps assumes normal user has some sort of sudo.
Unfortunately Windows 8.1 dumped UAC in the toilet when forcing the Windows 8.1 update to be downloaded from the store, which made your local admin account useless.
>This setup on Ubuntu and what I can remember on OSX is not hassle free because a lot of installers and apps assumes normal user has some sort of sudo.
On OSX you get an elevated privileges login prompt for any installer needing to write to / and even for many write protected folders inside your own homedir. You can grant rights as any user you want simply by entering that username (it's automatically populated with the current user)
This is true for properly written installers and apps, but since not everything is properly written, a related problem does crop up from time to time: an installer or app assumes the user has permissions to something that the "admin" group usually has access to, and therefore doesn't bother using the correct API to elevate. Even here, though, in the typical cases of installers and updaters, there are easy workarounds that at least don't require logging out or giving additional rights to the logged-in user: fast user switch or login(1) to an admin user, then retry from there.
The only thing Windows does differently here is that it provides a silent, non-admin workaround (filesystem and registry virtualization) for buggy applications, which works, but which can be problematic in other ways. Most notably, while OS-level workarounds are a clear win for older and otherwise unsupported software, they reduce motivation for developers to fix bugs in current software papered over by Windows' workarounds.
I don't think I've run into an installer that doesn't properly elevate since 2005... Most just shove things into .pkg with PackageMaker and everything's correct
