Whether or not one finds a commentary edifying and/or useful depends on what they wish to gain. But assuming that the motivation is to understand the meaning of the Biblical text in its original intention, then I would say one need not look any further then Thomas Schreiner's NAC commentary. I have often vacillated on what detailed level I should study a biblical text, as value is certainly gleaned from very technical commentaries with elaborate Greek and sentence construction discussions (and a billion footnotes) yet often one is better off with a simple explanation of the text.
With this balance to consider (and only consider if you only have time and money to afford one text, otherwise you should sample many additions to the literature) I have often been hesitate to pursue studies in the New American Commentary Series (the flagship series of the Southern Baptist Convention) for lack of technicality. However, the biggest factor on the value of the commentary, is not the series itself but the author, and I had no reservations, indeed, no hesitation on obtaining Schreiner's new work as soon as it was published. Schreiner in the past has brought us an excellent addition to the study of Romans in the BECNT series, as well as a wonderfully readable Pauline Theology that is both probing yet lucidly written for non-scholars.
Schreiner does not disappoint with this work. From verse 1:1 he brings to life the story of salvation history as Peter unfolded it to his readers, those who were blessed enough to live in the age of fulfillment. Schreiner's position is unapologetically calvinistic, made clear by his discussion in the opening pages about the true meaning of "foreknew" in its biblical context (1:2). Schreiner also emphasizes that Salvation in the Petrine context generally refers to future salvation, or salvation on the eschatological judgment day. Good works, which will indeed be judged by the impartial Judge in the future, are nevertheless rooted in God's prior acts of deliverance, and obtained only through the Grace of God imparting the Spirit for our benefit. As most Calvinist Baptists in the academic realm, Schreiner does not adhere to classic covenant theology, but non the less departs from dispensationalism by asserting that the promises made to Israel are now fulfilled in the church, and that ethnic Jews are in no way set aside but instead now must believe in Jesus to be part of the true Israel, and not simply by ethnic decen.
Overall, Schreiner strikes a good balance between exegeting the text, and elaborating its relevance to the modern reader (who is also living in the age of fulfillment). He compares/contrasts with other sources often, but the majority of this takes place in the footnotes so the reader who wishes to keep his focus on the text itself need not be hindered. Like all NAC volumes, the base text used is the NIV, but Schreiner is not hesitant to offer his own translations or agree similarly with a different translation (ESV, NASB, etc.) if in his opinion the NIV text is wrong or unclear. Schreiner interacts with the Greek text at a moderate to basic level, and per standard NAC methodology the Greek is transliterated into the text.
Schreiner demonstrates his breadth of knowledge in the secondary sources (like many commentaries, with a selected bibliography with more works then I have read in my entire life), though keeps the pace quick and the discussion inward focused on the text. The Books are split into sections and then subsections, with good introductions and beginning summaries of what lies ahead. Schreiner does a good job of reminding the reader often of the flow of Peter's arguments/exhortations.
For those of you who care about quality of printing etc., I would say you won't be disappointed by Broadman. The Hardbound book is solid and will sit well on any deserving bookshelf. The dusk jacket is a crimson red, a good looking cover all in all though it might seem a bit outdated in ten to fifteen years (Anybody take a look at the dust jacket from the NICNT from the mid 80's!). The book cover itself (minus the dusk jacket) is also quite solid, simpler, somewhat reference library like, and ultimately will have more staying power in style then the dust jacket. The book doesn't exactly lay open flat, making it difficult for study with pen and paper, but it need not by plied open either and is generally comfortable for casual reading. The pages are think and adequate for long term use, but lack any smoothness or texture that one finds in some more pleasantly printed volumes. Either way, they should be conducive to highlighting though I never actually did. There is little margin room for those who like to take notes. I don't know the actual name of the text type, but the style and size is conducive enough for reading.
All in all, if you can only afford in money and time resources one aid in the study of each Biblical book, I would recommend you look here for Peter. Schreiner is both exegetically solid and rigorous yet keeps an eye on the concerns and relevance of the material to the modern reader. Hats off to Schreiner!