I was working on a case where I had to empty a hidden field, save the form and refresh all without the user noticing it. In CRM 2011 you could only achieve this by doing a not so pretty refresh something like this:

function SaveAndRefresh() {
    Xrm.Page.getAttribute("myAttributeName").setValue(null);
    var id = Xrm.Page.data.entity.getId();
    Xrm.Page.data.save();
    Xrm.Utility.openEntityForm("myEntityName", id);
}

function SaveAndRefresh() {
    Xrm.Page.getAttribute("myAttributeName").setValue(null);
    Xrm.Page.data.refresh(true);
}