If you ignore circlejerk tags, and/or people who subscribe to the circlejerk/red.dit/cultofpersonality life then you have nothing to worry about. twenty minutes of ignoring tags and/or circlejerkers after syncretic quitting that other site, has made my hubski experience right back to where i like it. Splendid!
As far as ignoring individual people, I try to use a little more discretion. As far as ignoring certain tags concerning the other site, its helped clean up the signal to noise ratio. Thats just how i'm dealing with it, to make my experience cleaner. If someone else wants to make this their cool new lil "other site clone" spot and giggle around with their buddies and pat each other on the back for their contentless raving, thats fine for them, as for me, I decline. I'm choosing my own adventure, and they're choosing theirs. :)