The distinctions in this article are really important in this matter:
http://www.catholicapologetics.info/modernproblems/newmass/nmissa.htmSummary of Reasons why we shouldn't attend the New Mass
We are never allowed to have any doubts with regard to the sacraments, so if a sacrament is doubtful, we must not take part in it. Because of the ambiguity of the prayers in the New Mass, and because these prayers have an effect on the intention of the priest saying the Mass, there is doubt of his intention, and hence a doubt about the validity of the Mass. Hence we shouldn't attend the New Mass.
The New Mass is displeasing to God. This is because:
The various circuмstances that usually surround the celebration of the New Mass make us slowly lose our Faith.
The New Mass lacks something good it should have as a sacrifice worthy of being offered to God.
The New Mass is bad in itself, containing ambiguities and an actual lie about the words Jesus said at the Last Supper.
The New Mass is bad because of the purpose expressed in it.
The way the New Mass is celebrated most of the time has been condemned by infallible declarations of the Council of Trent.