I actually tried this and sent it back already, so I’m writing this a bit from memory. Basically, it didn’t fit. (But still less that $30 on Amazon!)
Since I love the Lucy (so much that I picked up another one somewhere; now I have both the navy and the pink, and it sounds like there are two new colors coming out soon!) and not so much the Marcie, it sounds like I’m a basic full-on-bottom shape. There are ways of distinguishing shape such as, for example, actually looking at the shape of your breast, but I’m shape-challenged and don’t figure those things out easily. This “full-on-tops often prefer Marcie and Lucy is a similar bra for full-on-bottoms” system is a safe one for me.
I had a lot of loose cup material floating around; essentially the top third of the cup was not being filled. It didn’t feel like the kind of fit that could have been improved by going down a cup, though. It was nowhere near as bad a fit as the Meg from once upon a time, though. The Meg was terrible for me, but the Marcie was just a little bad. Bad enough to not want to keep at this point, since I have enough well-fitting bras to do laundry at a reasonable pace, but not more than just a little bad.
Bloggy update: I’ve made some changes to the About page and plumped up the Resources page. Yay!