Respectfully, Matthew, it matters a great deal. Now, I'm not saying that personal communication, even deep friendship, between resisters, independents, strict sedevacantists, etc., isn't possible. This forum's success is proof of that. But the differences matter. To the resister, a sedevacantist is ostensibly violating precepts of Canon Law by personally declaring the See of Peter vacant. To many sedevacantists, resisters use a dubious liturgical rite and, more to the point, profane the altars of God by raising the name of the usurper of the Holy Seat, a gross and pertinacious heretic, there and pronouncing the Mass to be in communion with him.
These are not matters that can be disregarded as unimportant; they speak fundamentally to one's understanding and practice of the holy Catholic faith. As a matter of the faith, which the identity of the Holy Father as the focal point of religious unity and authority most certainly is, there cannot be two correct answers. The sedevacantist is wrong or the resister is wrong. Either Ratzinger is the Holy Pontiff, or nearly so dangerous enemy to faith and the salvation of human souls as him that was a murderer from the beginning. There's no middle ground and ultimately no unity, of liturgy or discipline, can exist between the two.