I made two batches. One following the exact recipe, and one with all butter. Defenitely use all butter, the icing turns out just as nice and there is no shortening taste.  -  12 Nov 2006  (Review from Allrecipes USA and Canada)

Great base recipe; I used all butter, no shortening. I used an extra teaspoon of vanilla and about 4-5 tablespoons of milk. I only used 2½ cups of powdered sugar and found it to be more than enough; I can't imagine the coma I'd be in if I had used 4! I used this icing on the One Bowl Chocolate Cake III (pictured) and I had some left over. The key is clearly to beat at medium to high speed for several minutes to ensure maximum peak. I do recommend this recipe provided you make some minor tweaks... I definitely suggest tasting as you go to ensure that you don't accidentally use too much sugar and have no way to remove the excess. Remember, the best recipes on earth still go through trial and error. =)  -  27 Jul 2007  (Review from Allrecipes USA and Canada)

I liked this. It had a milder flavor than other buttercream frostings I've tried, and I LOVED not having to cook it, and not using any eggs in it. As another reviewer pointed out though, it's absolutely unnecessary to beat the sugar in one cup at a time. Save yourself all that trouble and just pour all 4 cups in at once. I also used about twice as much milk, but that was just my preference. I suggest adding milk one tablespoon at a time until you have the consistency you desire.  -  30 Oct 2002  (Review from Allrecipes USA and Canada)