Well then, you are probably happy then that Sean Jonson doesn't participate on this forum anymore. Why should he, with the attacks from sedevacantists that he had to deal with?
Father Hewko is no sedevacantist, so this is no "sede attack". Father is corect about this issue, with Bishop Williamson giving a soft green light to the NOM. Sean's criticisms regarding the Sacrament conferring grace are well handled ahead of time by Father Hewko, who distinguishese between 1) potential grace and 2) actual grace conferred ... and who, while conceding that it may be debated theoretically, states that it's a dangerous opinion that could easily be construed as rendering attendance at the NOM acceptable to Catholics. Indeed, the Sacraments of the Orthodox are valid (more certainly than the NO Sacraments), and yet, if some woman asked, "I don't have access to daily Catholic Mass, but there's an Orthodox church near me, and I would like to receive the graces from the Sacrament," no Catholic in their right mind would respond, "well, you would receive graces from the Orthodox sacraments, so it might be OK for you to go." Or, similarly, of a Satanic Mass, "Well, although it's Satanic, if you go there and receive the Sacraments with the proper dispositions, you could receive grace."
Do we believe that the NOM is a sacrilegeous bastard Rite of Mass or don't we? If we don't, we might as well just head back to the Motu or even the local clown Mass.