I read both standard notation and tab.  While I learned standard notation 35 or so years ago I only started using tab a few years ago.  I was quite young when I learned standard notation so I don't remember how difficult it was to learn.  I like tab because I am a visual learner and tab shows be the positions along the neck.  I am constantly altering the positions because the more ways that I can play a piece the better I become.  Also this prepares me for improvisation.  I understand what you meant when you wrote about how those who read standard notation tend to play the score exactly as written.  I have learned that when I practice a piece of music to the point that I can play it without thinking I am able to change the complete voicing of the piece.  When I do not have a score practiced to the point of muscle memory I am not as able to breath life into it.  One reason that I have grown to enjoy learning a piece through tab is that the duration of the note is not defined as precisely and I grow more intuned to the relationships of the notes to each other and the note durations most often seem to naturally fall into place.  While learning through standard score I start off by being locked into the timing of the notes and I find this to be a very left brained experience.