Here is what I personally think. Lots of people here would disagree.
Don't take me, another low level ice dancer, as typical. I like my edges
extremely sharp. The ability to shim fingernails isn't good enough. If I walk with my edges off ice on a rubber mat, which I don't, they bend over or scrape off in 1 or 2 steps. I use guards, and re-straighten the edges after stepping onto the ice. I clean up (mostly not re-grind) my edges off-ice every few days.
I use 3/8" ROH, but some very good dancers get by with longer ROH. ROH and sharpness are not the same thing. A keen edge, which involves the suddenness of direction change in the last few thousandths of an inch of the edge.
Edges should be level. Slide a nickel down the blade - if it doesn't stay perfectly level to the eye, it's way off. If the hollow or the side has scratches, you will slow down, which may or may not matter to you.
I've been told that ice dance judges look at the width and uniformity of edge tracings, and that they usually want silent edges, but I don't know the details. Really sharp blades help A LOT.
It also helps A LOT if you align your weight + centrifugal force + other inertial forces precisely down the orientation of the blade, so there is very little sideways force on the edge to cause slippage - except on certain moves like edge changes, where people are supposed to hear a push against the edge, though not a slide.
Blade cost should be irrelevant to edge quality. But thin blades, like MK Dance, are cleaner and faster. Short tails make it easy to keep your feet close together without tripping. So I think Dance blades are better for us, but there are no cheap dance blades. Some cheap blades have soft steel, which must be sharpened more often. For me, the rocker profile of Ultima blades are harder to control than MK blades, and are evil. One thing I hate about Ultima blades, that extremely small angle control problems changes the way they interact with the ice, is loved by some people here.
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Talk to your sharpener and your coach to see if they have any ideas of what they and you can do to make your ice dance edges cleaner. That is probably the biggest thing!