I have more than one slow cooker and they all work differently. The "low" on one is almost a slow simmer and on the other it's no where near a simmer. So I think I would have to say it depends on your slow cooker. If it's something you usually brown first before you start the braise, I would do that and then let the slow cooker do it's work checking periodically until you know the workings of your particular slow cooker.