This is a well written commentary that is rich with references that feed into the meaning of each verse. The strong emphasis on sovereignty that good Presbyterians typically comes through in Boice's perspective (unique among the commentaries I have read) on why John wrote these letters. Boice skips all the statements by John in the earlier part of the letter where he says 'we write to you because...' and focuses on the last one in chapter 5. Boice says John didn't write for any other reason that to give the Christians assurance of their faith. The exclusive focus on assurance is not found in any other commentary I have read. This is Boice's strength. He brings unique concepts to the table. This is also his weakness. He has a bias towards the distinctive doctrines of Presbyterians. And this commentary clearly shows this bias.
Yet even with the bias, this is a commentary that will feed the spirit with rich cuts of prime steaks. He is no slacker when it comes to thinking through the exegetical nuances of a passage. Even if you are not a Presbyterian (and I'm not), you will be blessed by Boice's thoughts. He's provoking and passionate about his faith in his expressions in this commentary.
One point that I might note is that on some of his lexical work I was left wanting more. For example, in discussing 'ilasmos' the word often translated propitiation in 1 John 2:1-2, Boice tilts towards a legal definition giving almost a courtroom impression of this term. However, Smalley and others show extensively why this should not be viewed as a legal term in John, and Smalley gives the preferred meaning 'intercessor' or advocate in that sense of the word. So sometimes Boice is brilliant and other times I am left wanting a fuller explanation. This goes to show that it's good to consult more than one commentary, especially on crucial verses like 1 John 2:1-2.
If you have thought deeply about the links between John 1:1 and Genesis 1:1..and the differences between the related passages, Boice will tie in to these concepts intelligently and in a way that is easily grasped and convincing. Overall I am very glad to have this particular commentary and highly recommend it to everyone. I use it quite often and it is in my top five commentaries for John's letters.