I don't think there is anyone who keeps up with everything on NGA- that would be a LOT of time!
Just like with other technology, we have to figure out the best way to organize it to suit our individual preferences. (As an aside, I've been reading "Getting Things Done" and the technology organization is the hardest!)
Personally, I star things that I want for reference, but I watch loads of things that I just want to keep an eye on. I never (or extremely rarely) look at my watched threads, but I rely heavily on the stars to keep info handy for me.
