My gauge turned out almost right on. Blocked, mine turned out 7.75 in across the chest, so 15.5 in around. I used US 6 bamboo needles, even though the yarn wrapper said to use US 7-9 needles for a 4 - 4.5 spi gauge. I think since the needles were smaller, the material didn't turn out see-through.
The seed stitch dress hem curled until I blocked it. Now it's flat as could be, thank goodness!
ONE IMPORTANT PATTERN NOTE: I made the back left shoulder strap 2 inches longer to accomodate the button. I found that if I hadn't done this, the height of the left shoulder while buttoned would've been noticeably shorter than the right shoulder. In hindsight, this makes sense because all four shoulder straps are knit the same length. You'll have to see what happens when you get there to that part of the pattern. The pattern was easy to follow until I got to the shoulders. You'll find the front shoulder instructions mislabeled, so just switch them and remember that the buttonhole goes on the wearer's left shoulder and that the sts that get put on a holder for 3-needle BO need to match (front back right shoulders). The back shoulder instructions are OK, except that, as I mentioned above, you'll need to lengthen the left back shoulder to accomodate the button.