I'll add to all of this that the music is simply different due to technological advances. For example, a radio host in New York, and good friend of mine, upon its release mentioned that the latest Spanish Harlem Orchestra cd was "too clean." It sounded too perfect. He agreed that the cd has some good songs, but didn't exactly like that it was so "clean."
This trend is readily observable with a lot of the "salsa dura" that bands are recording lately. This perfection has the effect of making a lot of the new salsa sound very similar. Producers need to be cognizant of this situation and be more creative and innovative with the overall sound, but especially the bridges, breaks, etcetera.
Newer salsa is much less jazzy; which is a quality that a lot of the more accomplished dancers appreciate in the music. The jazzy sound of salsa was very popular in the late '60s and '70s.
Also, newer salsa is much less percussive; which is another quality that a lot of the more accomplished dancers appreciate in the music.
Lastly, as in an article that was posted in salsaforums somewhere, the homage to African deities is absent from newer salsa. That trend essentially died quickly as the salsa industry sought to cross-over to mainstream audiences. No longer do we hear songs paying homage to Ochun, Yemaya, Obatala, etcetera.