I have the final Serena Williams duo for you, which was released in conjunction with the US Open (if you hadn't heard, she released duos with the other major tennis tournaments this year as well, France, Australian, Wimbledon).
This is the first duo that doesn't come with some sort of "effect" along with a color - the others either came with a shatter polish or a super glitter polish. This duo came with 2 glass fleck shimmers, which I quite like. I'm starting to step back from the uber effect polishes and steer towards the subtle effect polishes again (that isn't to say I haven't been loving my chunky glitters, because I have. Just am a little done with the crackle and super over the top glitter/glass fleck/duochrome combo polishes).
The two colors in this duo are a bronzey orange glass fleck and a super opaque, bright reddish pink glass fleck.
I wasn't too keen on these when the duo was first released, but slowly it started to get my attention over and over again on different blogs and I finally decided I needed it.
I purchased this on AveYou.com, but I've seen it at Ulta as well as my local beauty supply stores.
Pros & Bronze
Orangey bronze glass fleck polish. It's got a slight reddish pink duochrome to it, making it very very warm and sunny at one angle and then it changes like fall leaves to a rustic cranberry red color at another angle.
It reminds me a lot of the Burlesque shimmers from last year, the two orange/bronze ones.
It was a little on the sheer side, I'd even go 4 coats (3 is shown at the bottom) just to get a good, thick color but that's just me. It doesn't wear thick so that's nice.
Love Is A Racket
Bright reddish pink glass fleck. It reminds me of OPI's Dutch Tulips in color, but the finish is different. The glass fleck in this polish is a nice bright pinky magenta, similar to that you'd see in Alegra by Zoya.
This one was much more pigmented than the other. Perhaps you're meant to layer a single coat of Pros & Bronze over this? I don't know. I like this on it's own though.
It dries a little dull so you'll definitely need a top coat. It's opaque in 2 coats though.