DeMaistre, I've had a further think about all of this, and would offer the following point of view.
If the reality turns out to be that the Holy See is filled and the Pope (for better or for worse) is Benedict XVI, then you do not want death to find you a member of a sedevacantist chapel. If that happens, you will die in schism and you will go to hell. If you die in schism, all of your piety, orthodoxy, and good works will not be able to save you.
Raoul76 & Co. want you to believe that they alone see reality, and that the reality is that Benedict XVI is an agent of the devil and an anti-pope. By what authority do they make this most disturbing claim? They will say that it is by the authority of the infallible magisterium prior to Vatican II (or prior to 1914, according to CM). All that it takes, they will tell you, is a common sense application of the infallible magisterium to the present situation, and voila! -- Benedict XVI is proven a manifest and pertinacious heretic and the sedevacantist thesis becomes instantly binding on your conscience. If you do not subscribe to the sedevacantist thesis, you follow a heretic anti-pope and are a willing thrall of Satan. Worse yet, you divert needed funds from Raoul76's coffers. :-)
Now, stop right there and pay very close attention to what I'm about to say.
The ultimate authority behind the sedevacantist position is the infallible magisterium as reflected in the teachings of Holy Mother Church prior to Vatican II (or prior to 1914, according to CM). However, the proximate authority behind the sedevacantist position -- by the sedes' own admission -- is common sense. "Of course Benedict XVI is a heretic anti-pope! It's common sense! If you cannot see it, you are culpable and guilty of grave sin!"
Such is the "authority" behind the sedevacantist position. What is the authority behind the anti-sedevacantist position? I submit that both the ultimate and proximate authority behind Benedict XVI's claim to legitimacy is ... Benedict XVI himself, i.e., the man who was elected by conclave and claims thereby to be the real successor of St. Peter. In the absence of a rival claimant to the Chair of Peter (a rival who emerged from the same conclave as Benedict XVI), no one else can claim proximate authority in the name of Our Lord Jesus Christ to settle the matter of whether Benedict XVI is a valid Pope.
Upon what authority do you want to stake your eternal salvation? (Remember what becomes of your immortal soul if in objective reality you die in a state of schism.) Do you choose the authority of the one man who claims (and has the act of a conclave to back up the claim) to be the rightful successor of St. Peter, or do you choose the "common sense" of Raoul76 & Co.?