Will the Fixxer work with my Hed (Spinergy, Trispoke, etc) wheel?
No, probably not. The Fixxer works with Shimano brand Freehub bodies only - and even then some Shimano hubs will not work. Note that DuraAce 10 speed is a no go as is pre-97 DA. If you don't know what kind of freehub body your wheel has, please contact the wheel manufacturer for this information or Google it!
This means that your hub must be a Shimano brand hub - not just any hub that works with Shimano-compatible cassettes. Cool? In fact, just read this, ok? http://surlybikes.com/blog/spew/spew_fixxer/