This may be *very* late, but I just did a review on the Satin Princess Cinch (found here: My Corset Is In Another Castle...
Unfortunately, it is not suitable for tightlacing
Most of (if not all) the bones in the corset are actually plastic. Only the busk is metal, and while the bones that sandwich the grommets *may* be metal, it isn't a good quality, because, just like the plastic bones, they warped and poked into my back. I also have pictures of the plastic boning from the Satin Princess Cinch, so that you all know I'm not just talking out of my hat, here.
So, in short, unfortunately it's not for tightlacing, and is not metal boned. I advise finding a corset with spiral steel boning if you're looking to tightlace. I know I was very let down by the corset having plastic bones, especially since the description says: "features double metal boning throughout the construction of the garment for the sturdiest and most effective shaping".