We had them for one rehearsal before the show.
We got regular trumpets, lycra instead of velvet. We ordered all different colors, wanted to look cohesive rather than uniform. You can see them here:
(sorry about the embedding, just click anywhere besides the button)
There's a little saiidi-style movement around 1:06, but it's not big moves. The skirts don't feel restrictive at all, though. With a fishtail you should be in great shape!
We added about an inch to our measurements because I've found the skirts tend to ride up if they're too tight. They don't have to be tight to be slinky, and it's easier to move this way.
On Lora's advice I order mine really long, measure all the way to the floor. She talked me into a 40" instead of a 38" for my first one -- I'm 5'9 -- and I was so glad.