Combine broccoli, red onion, bacon, sunflower seeds and raisins in a large bowl. Toss well. Combine vinegar and sweetener in a small dish. Taste to determine personal preference for sweetness. You can add a little more of either ingredient to adjust the sweetness for your likes. Pour dressing over the ingredients in the bowl and toss well. Cover and chill at least an hour. Toss again before serving. Keeps well for several days in the refrigerator.