As others have mentioned, taxes are vary from jurisdiction to jurisdiction. I was fortunate (or not :-)) to have a mother in law who was both a CPA and ran a tax business. In my case I got to consult with her on a variety of "what if I did ..." scenarios. In the case of my Sun stock it was clear of the option restrictions but having been acquired (remember that $10M+ of "future" wealth?) I had a pretty incredible "income" on paper. But really it was all about restricted stock (as part of the acquisition) and 89b elections etc.

Anyway, the meta question of whether or not to pay off my house was real (my mother in law advised against, after all you get the mortgage deduction). The endowment question is also good and I find myself in the Vancouver situation in a house that I probably wouldn't spend as much as its "worth" to live in it. Future risk/reward never goes away.