In a sermon given by Fr. David Hewko on Sunday September 1, 2013 he tells us that we ought not to go anymore to SSPX Masses because the neo-SSPX has compromised. Here is the relevant extract from that sermon (left click to the left of the 00:00 marker to play) along with a downloadable mp3.
In a conference given by Fr. Joseph Pfeiffer on Saturday August 31, 2013 in Levis, Quebec, he explains again and in a bit more detail how the first condition, officially determined by the 2012 SSPX General Chapter as essential prior to a canonical regularization, offends the Faith and is therefore morally unacceptable. The relevant extract (14 min 0 s to 17 min 50 s) of that conference is below.
Two previous postings on this matter are here and here.