Pick one. I'm kind of digging the smooth-as-glass, but let's have a vote.
[snip] [snip]
I'd go for smooth-as-glass. Sure it's not entirely realistic but so is the rest of the scene. It's pretty stylistic, but also rather fitting.
One suggestion I have is to have the jet-trails sort of fading out gradually, as shown here:

Well really it's just personal taste, but this is usually what I see happening when a jet leaves its trail across the sky. The highest jet is the only one that's really significantly affected. I also anti-aliased the birds slightly and made their reflections lighter. And there are a few spots where the smoke still needs to be cleaned up.. yeah, I know.