Everyone likes it so much they pass it on to their friends!
I find the guard almost useless. If I'm doing nothing but ripping for a week, I might think about putting it on. I don't like not being able to see the blade clearly but the dust collector works better with it on. ;-) I use the knife whenever I'm making through cuts, though.
You'll use the inserts. You'll probably want to buy more, if you do a lot of dado cuts. Did I mention that Forrest makes a nice dado set? ;-)
I really like my JessEm miter gauge (JessEm makes great stuff). The Incra 1000HD is really nice, too, though not as solid.
Use it for another tool? I don't think you'd get enough for it to bother selling it.