Make quick search scope a site configurable option

Our Confluence installation has around 150 spaces. Many of our users complain that "Quick Search" defaults to searching in all spaces, which makes it somewhat less quick since users always have to limit it to specific space searching.

I realise that many users with smaller Confluence instances would not mind this behaviour so can we have a site-wide configuration option to configure whether quick search searches the current space or the global installation?

It would also be very handy if there was a user preference that allowed the user to configure quick search behaviour on the home page - to specify either global search or limited to the user's favourite spaces.