Good question. Good responses. Depends on the song is my vote for sure.
From studying classical guitar, you rarely barre a chord in the traditional way because you need all your fingers to be fluid and ready to move up and down the neck - of course it needs to sound good, but if you watch a really good classical guitarist, they are so smooth that you sometimes can't even tell what strings they are pressing. My personal inclination is to figure out a way to partially barre, or not barre at all and just do the notes I need. But I don't have a lot of hand strength so I get better sound that way. I agree with the others when they have you watch for the chord you might transition into from the barre, or the chord that precedes the bar. I think you are on top of it.
