Although not the subject of this review, I will say up front: I love the John MacArthur Study Bible. If the editors had just included a concordance....(hint)! So now that you know that....
It goes without saying that the NASB text is peerless in it's accuracy. Period. Too, I have always admired the wealth of notes extant in the NIV Study Bible. Not to beat a dead horse, but the problem there was the NIV; the Study Bible part was great! Now the best of both are merged into the Zondervan NASB Study Bible, and it's wonderful!
While not perfect (as other reviewers have pointed out), it's the best conservative evangelical study bible to date. (Subject to change when the new MacArthur Study Bible debuts!).
While the depth of the commentary is obviously limited in such a work, the breadth is exhaustive. The strength of the notes are in their helfulness everywhere--not just in long-winded commentary on controversial passages.
The index, concordance, maps, etc., are sufficient for most everyone, and, as a whole, far better than most. I never thought I'd say it: we've come a long way from Dr. Scofield!
In summary, you'll be hard-pressed to top this work. Despite its (few) minor annoyances which other reviewers have greatly exagerated, the Zondervan Study Bible is the best of its genre in print today. Are you listening Dr. MacArthur?!