I personally prefer the workmans when I'm actually working (I'm a professional cinematographer/gaffer - though I admit I was working on a TV show last week and wore a Survival one day, and an original corduroy the next since it was so cold - 3F and shooting exteriors). For day to day wear I am usually in my denim or one of my two cords (Brown test model and blue production model - which I had planned on dying black, but the blue has grown on me, it's nice to have a UK that is not in an earth tone).

As for the pockets being interchanbeable, on the workmans they are not, but you could remove them and add snaps yourself if so motivated.

Adam