Peeking inside, the first thing I read was the introduction by R. C. Sproul. It's a page and a half and provides a very quick recap of the history of the Reformation. It's interesting as far as it goes, but I think a lengthier article would have been appropriate. After reading that introduction, I thumbed through the rest of the Bible and found very familiar features: introductions to each book, two columns of text, two columns of study notes, a center column cross-reference system, maps, charts, etc. One of the features I really like here are the introductions to major sections of the Bible (Pentateuch, Historical Books, Hebrew Poetry, Wisdom Literature, Prophets, Intertestamental Period, Gospels an Acts, Epistles). These introductions are about two pages long, so they provide a quick overview without getting bogged down into details. Throughout the Bible there are also about 100 short "theological notes" on various subjects such as miracles, satan, the sacraments, resurrection and glorification, and heaven. I suspect that these notes are were most of the reformation theology is going to be found (see, e.g., the note on "The Lord's Supper").
I read through the notes for Jonah and I like them. They're not overly stuffy, but they have some depth to them. They are pretty similar to study notes I've read in other editions. All in all, they're very readable, and make a good pairing with the ESV text.
My overall impression of this Bible is that I like it, but I don't think it's going to bubble up to be one of my favorite editions. The overall study notes are comparable with other editions. The special features are interesting, but kinda fit a niche market. And for a Bible that claims to be a Reformation Study Bible, I'm not sure that there's enough study materials about the Reformation to really stand out. I suspect that I would find this more useful if I were directly studying the history and theology of the Reformation. Right now, that's not where I focus my studies, so I'm not really sure that I'm the target market for this Bible.
I have a feeling that the more time I spend with it, the more I'm going to end up liking it, though.