My new ESV Study Bible arrived in the mail today. Just a few thoughts after looking through it for the last half-hour...
1. It's much bigger than I had anticipated. It's not so much the length or the width, but the thickness. It is a little over 2 inches thick, probably a good half-inch thicker than the Reformation Study Bible.
2. The quality of the Bible appears to be excellent--solid bindings, good quality pages, etc.
3. There seems to be a wealth of good articles and resources at the back of the Bible: There's an overview of Biblical Doctrine, an overview of Biblical Ethics, an article on Bible manuscripts, as well as a section on cults and world religions.
4. The online version of the ESV Study Bible (everyone who purchases a ESV Study Bible has access to this) looks to be really good!
If you are looking to buy one (or, for that matter, if you are looking to buy some books for Christmas gifts), I would recommend Monergism Books. This is the place that I buy most of my books from. Turn-around time is incredible (I ordered some stuff on Monday afternoon and it came today) and you can't beat the shipping ($3.99 no matter how much you order).