The question is whether a sharp edge or a softer edge is "better" on cakes. The interesting thing is that while many decorators seem to be in the "sharp edges is better" camp, my clients are still about 90% in the "softer edges are better" camp. There's a lot of bickering about this online, which is pretty dumb, in my opinion. Just relax...It's a decorating choice, and if the client wants one or the other that's what they should get, regardless of whether some cake harpy is going to start hyperventilating because it wasn't done "the right way."
I was covering some dummy cakes today, and while I could have done a really sharp edge on those by virtue of the fact that they're styrofoam, I opted not to. I like the edge to be somewhere in between totally rounded and sharp-enough-to-cut-your-hand-open. I'm not a huge fan of either extreme, to tell the truth.
As I was covering the dummies, I also remembered that when I was in culinary school and we had to cover a dummy, we'd actually take sandpaper and use it to get rid of the sharp edge on the dummies that we used then. Nobody wanted a sharp edge on fondant back then.
You can even buy rounded-edge dummies to take care of this problem, and those would definitely give you a rounder edge.
And apparently the sharp edge is not as universal as people would have you believe. In the most recent issue of Wedding Cakes: A Design Source, which is a compilation of a lot of high-quality design work, I counted one sharp-edged cake. One. All the others had a softer edge, and some even had an extremely rounded edge.
So when you do your cakes, do whatever you want, but remember that it's a style, not a standard. Some designs would probably look better with one or the other. Being able to do both is a plus, but claiming that one or the other is the only way to do it isn't accurate.
Kara Buntin owns A Cake To Remember LLC in Richmond VA, and cake supplies online at www.acaketoremember.com and www.acaketoremember.etsy.com