It depends on how big it all is when it comes together. For example, you'll have 7 plugins (and associated code that runs them) that won't be used at all on th

It depends on how big it all is when it comes together. For example, you'll have 7 plugins (and associated code that runs them) that won't be used at all on the splash screen. That's going to increase load-time when someone hits that page. If someone hits a page direct and avoids the splash screen, it's not going to be cached in the first place so it'll all be loaded. Only this time they're loading 4 plugins and the related code that won't even be used. IMO you should compress what's needed for each page. Several smaller downloads is often better than one large download, and you shouldn't be relying on a user's cache to gauge your own site's performance. If you're not going to use it, don't include it.