I definitely support the position of the SSPX.
As for the Indult (in which category I include those TLMs being celebrated in the wake of the recent Motu Proprio), while I think that what they're doing is meritorious and perhaps well-intended, I'm a little hesitant to attend their Masses. There are theoretical and practical reasons for my hesitancy.
Theoretically, the priests who operate under the Indult must accept Vatican II and not question it. This presents a problem because Vatican II -- or at least its interpretation -- has led to the gross abuses in the liturgy that has, among a few other reasons, resulted in their being a traditional Catholic "movement" in the first place.
Practically, the priests who celebrate the TLM under the Indult dont always appear to know what they are doing, or they "blend" parts of the Novus Ordo in with the TLM.
Case in point. I went to an Indult site for the Feast of the Assumption this past August, in accordance with it being a Holy Day of Obligation. I did this out of a perhaps misguided sense of Charity: not in the sense of fulfilling my obligation, but in the sense of thinking that I was being perhaps "open-minded" towards the Indult.
In this case, that was a mistake.
While the Mass itself appeared to be picture-perfect, the Epistle and Gospel readings were not the ones they should've been. Turns out they were the ones that the Novus Ordo does because it is on a three-year cycle. My two sons are too young to understand the difference, but I did. I havent returned since.
I dont condemn the priests who operate under the Indult: I know they probably are trying to make the best of a bad situation. But, by focusing solely on the TLM and not on the doctrinal problems that have arisen since Vatican II -- indeed in declaring that they will not even question them -- I think they are shooting themselves in the foot by focusing more on Form rather than on Substance.