This is my own, honest, 100% honest, opinion. Pleas respect my opinion and realize that it just the opinion of one sinner.
I think Bishop Fellay has a very difficult job and position. On the one hand he has to interpret his mentor, his consecrator, Archbishop Lefevbre in an authentic and true manner. On the other hand he has clamor from BOTH spectrums of the argument. From the resistance he is a liberal. From Rome and the ordinaries, he is a nαzι and Radical. From his own sheep, the people are divided. Yes, he is a Bishop but, at the end of the day, he is only human and keeping the "ball rolling" is part of his job.
I believed, 100%, that the SSPX would be a personal prelature before the end of the Year of "Mercy." I think the intention of ROme with the granting of jurisdiction was to slide them into a Prelature or other agreement.
The recent declaration, I believe, is very strongly worded. If Bishop Fellay wanted an agreement he would have left the door more open or would have opened the door fully and taken advantage of this "Year of Mercy" and signed Rome's agreement.
Still, I do not trust him fully. Do I believe his sacraments are valid? YES! Without a doubt. Do I think the priests he consecrates are validly consecrated priests? Yes! Absolutely! Do I think he is human and sometimes gets hazy eyes when he sees ROme and the purple buttons and the birettas? Yes. He is human. As am I and you. However, after the recent declaration, I feel "safe" that the SSPX will continue being the ship in the violent sea of confusion as a place of peace and Truth. The Society is in the middle of a storm and it's bound to get wet sometimes.