Well, no, it is not the best solution by a wide margin.
There is no reason Firefox has to go into a system ProgramFiles directory when it is installed by a user. It needs to go into the user's ProgramFiles. If it is installed by an admin, then, yes, it should go into the system directory, and it is reasonable to have the updater process run as a system service. But if it's me, Joe User, installing Firefox on a shared box for my own use, then (a) I should really be able to do that within the confines of my account permissions (b) the updating mechanism should also fit into the same set of restrictions.
Just think about it for a minute.
PS. "Google and Mozilla aren't idiots" is not an argument. Microsoft aren't idiots either, but look at Vista.
But Firefox already works like that. If you install as a (non-admin) user, it goes into your user dir and there is no update service.
If you install as an admin user, it goes into Program Files, and by your own admission, there's no other way to update it than to have the update service.
There is no reason Firefox has to go into a system ProgramFiles directory when it is installed by a user. It needs to go into the user's ProgramFiles. If it is installed by an admin, then, yes, it should go into the system directory, and it is reasonable to have the updater process run as a system service. But if it's me, Joe User, installing Firefox on a shared box for my own use, then (a) I should really be able to do that within the confines of my account permissions (b) the updating mechanism should also fit into the same set of restrictions.
Just think about it for a minute.
PS. "Google and Mozilla aren't idiots" is not an argument. Microsoft aren't idiots either, but look at Vista.