Here are my comparison swatches for Marabout and Chiffon. Hope this helps! Click to enlarge :)
1 coat each.
2 coats each.
Positively Posh kind of needed the 3rd coat so I did them all lol. Positively Posh and Marabout are pretty much identical. I needed something on my pinky hence Prince Charming but it is lighter. If you want to see an OPI You Don't Know Jacques comparison check out Kellie's blog here.
I also included a Chiffon comparison but apparently I don't own anything similar.