There’s no comparison between Marshall and Vigano.
And regarding the latter, he has made contributions toward the recovery of the Church which nobody else has done, such as explaining how Vatican II may not even be a true ecuмenical council (the implication being that it could all be flushed down the toilet tomorrow without doing any injury to the corpus of Catholic doctrine).
I have to agree with Sean here. At least +Vigano is a cleric, and a prelate. He is deserving of Catholics' attention. Also, he knows much more, has said much more, and has done much more good for the Church than Marshall.
A lot of +Vigano's letters and writings sounds like +ABL or +Williamson at times. He seems to really know what's going on. Maybe he'll become more like +ABL with time, who knows.
I wouldn't put +Vigano on the same level as +ABL, +Williamson, or the other Resistance bishops -- but I'd put him above all the lay talking head personalities in the Blogosphere.