It's interesting -- to say the least -- that an interview like this was done on the eve of a formal "acceptance" of the SSPX by Conciliar Rome.
Now +Fellay is going to be coming from a position of weakness, and will be all the more HUNGRY for that recognition from Rome. It really makes me wonder whose idea this interview was?
For +Fellay, this must have served somewhat as a wake-up call: just look at how The Modern World holds IN HORROR the true Catholic position on just about everything.
I agree with the previous posters that +Williamson is much more battle-hardened, wiser, and more experienced. He could have handled an adversary like this much better. Plus +Williamson says what he believes -- think back to that infamous interview +W gave which caused him to get into such trouble with +Fellay. At least +W was composed and in control during that interview. He knows what he believes, and is willing (and able) to explain it to you, in all nuanced detail.