I've made the Kellie dress twice, one worn for a wedding, very comfortable to wear.
A tip, it's quite close fitting so if your fabric has just a little stretch it's worth adding a little extra seam allowance. The 2nd one I made had more stretch and I ended up taking the side seams in.
Also if the fabric has a pattern take care in placing the front as the neckline ends up being at about 2 o'clock to the skirt or lower part. You'll see what I mean when you put the PDF together. I'd say cutting it out was the most complicated part! The top is also self lined so you may need a plain knit if the fabric has a light background and print can be seen (that happened with the one I wore for a wedding.
Think I'll get the Iris dress, been looking at it for a while when there have been offers.