Thanks. I've added plain and cherry to my shopping list.The bottles are 250ml. I think you get 'more value for money' if you take it in a short time frame, no more than 15 minutes. If you drink a bottle throughout the day, I think the bowel may well get suboptimal dose, you need it down there working.
Flavours - cacao, wasn't quite to my palate; cherry, very mild taste and lovely; plain, very nice, nowhere near tart enough to make your eye screw up. I am not troubled about flavours - they just aren't strong enough to demerit from the intended good.