Alas, my experiences are from about 33 years ago now. I felt that STAS in the late 1980s / early 1990s was of decent quality. You did cover the necessary material, even though it was obvious that only about 10% of the seminarians actually absorbed it ... doing just well enough to pass through. Similarly, the professors did not exactly have advanced degrees. Some of them became seminary professors pretty much "fresh out" from seminary themselves. Nevertheless, those who were bright could take advantage of the classes and get a very solid education. Apart from the academics, I found the formation there to be solid ... excepting a small tendency among a few there toward something that almost had a Jansenist flavor. There were a group of 7 in particular to whom we jokingly referred as "The 7 Penitential Psalms". Unfortunately, that "strictness" took a big turn with the next generation of priests to an almost worldly spirit, a transformation that began under Urrutigoity. After that, I can't speak much to it. Where I leave off is about where Matthew arrived on the scene, and he could probably pick it up from there.
Bishop Sanborn's seminary was very solid academically ... although during the brief time I was there, it was just two of us studying for the priesthood, so the overall formation was almost non-existent.