The trouble with Sasha's Charlotte spiral was that it was on a shallow edge or no edge at all.
This picture shows that very clearly.
http://alainagyogini.files.wordpress.com/2010/05/sasha_cohen_charlotte_spiral1.jpg
Here's Sasha's regular spiral-beautiful position, and a good edge, too.
http://web.icenetwork.com/images/2007/12/17/jGFvNmpO.jpg
The trouble with Yu Na's spiral
esthetically to me is that she really, really does not like to point her toe, and the rules do not require her to do so to get great scores on the element, so she doesn't. Also she has not needed to develop turn out, so her butt sticks up. And she does not fully extend her leg, so it's not straight. BTW, this is the improved version from last year.
http://graphics8.nytimes.com/images...2yuna_ringsblog/22yuna_ringsblog-blogSpan.jpg
and from another angle and time
http://web.icenetwork.com/images/2009/10/17/TRKnBPyj.jpg
On the other hand, as you can easily see from these shots, her spiral is on a great edge, and (although you can't see it from a still shot), her spirals have wonderful speed, and so they score well in GOE. Any problems with the esthetics of her spiral would fall into PCS, and since the rest of her skating is really amazing, it does not show, really. So I suggest people do what I do-if you find the appearance of YuNa's spiral unesthetic, turn your head and don't look. The performance will be wonderful immediately after she stop doing the ugly spiral.
A COP spiral, in general, is only very marginally better or worse because it is esthetically beautiful. For example, I don't know whether I've ever seen one of those dog-pee spirals that I though was even remotely pretty, but the skaters needed another spiral position they could hold, and so many used that one. I am so glad that the spiral sequence is now a Choreographic Spiral sequence instead. Thank you, ISU!