I've always used Blue Bonnet in my baking, and never had the first complaint or noticed a difference. I've also never omitted anything else from the recipe. Didn't know I needed to! LOL Can you tell I was raised by someone who cooks straight from a can most of the time? (but I'd walk a hundred miles, uphill, barefoot, in the snow, to get one of her made-from-scratch pies)
I used to use BB in my icing, as well, but noticed recently that for some reason, it seems to be breaking down after an hour or two in the decorating bag. NOT good. And it never did that before. I have to wonder if they've changed something in their formula. But I've switched to butter for the icing, and have noticed a big difference.
I have subjected friends and family to a taste test with the NFSC, though, and none of them could tell the slightest bit of difference between butter and margarine. Since margarine is so much cheaper, I stick with it for that and my cakes, but for icing, butter will be it for me from now on.