I'm not sure there's a best answer for this, but for what it's worth here's how I deal with membership in three Chatter clouds.
My three Chatter clouds:
- Enterprise org: for internal use only
- App org: also for internal use
- Higher Ed Cloud: created by the Salesforce Foundation for inter-institutional collaboration
To start my day, I login to both the Enterprise org (hosted on NA1) and the App org (hosted on NA11) with my default browser. This allows me to click links in the Chatter digest and notification emails to go directly to the Chatter thread to post a response. For the Higher Ed Cloud, I'm connected using Chatter Desktop, which allows me to post quick responses to new posts and comments because the composite Chatter feed is sorted by both Post & Comment Date.
I suspect that for those of us who aren't as fortunate to work in orgs that are hosted on different servers, we have to rely on the Chatter Desktop feature that allows fast switching between different orgs, which works pretty well in my opinion.
But in the end, how much collaboration one can handle across all media depends on what each of us value. Setting up Chatter to send notifications on every post and comment anywhere may not be a commitment suitable or desirable for everyone.
