I think it is about time to work out this network option better. Just a few examples, I'm network admin, but I have to visit each subsite to remove spam. The same if I'm (de)activating plugins, change plugin settings (network activate does not make network settings, not even for an Automatik plugin such as Akismet). That sort of things are more time consuming than necessary. Also there is no easy way to switch from one subsite to another. I now edit the url in the browser to go the plugins of one subsite to another, so I don't have to go via the dashboard.
Wouldn't it be something to have an actual network admin dashboard in which you click on 'plugins' and see all subsites' plugins, settings that are for the whole network (permalinks, discussion, reading, etc. are all the same in my subsites), one 'flush spam' button, a settings page for network activated plugins, one export function, sitewide comment moderation, etc., etc.? The only things 'network admin' now are that I don't have to logout and login each time I switch sites, the admin bar on top (a good start, perhaps making that customisable is half the job) and the fact that I can edit the theme for all sites in one place, but that is it. More network admin please :-)