I just finished reading this commentary, which has been valuable to me in preparing sermons through Matthew last year and the last couple weeks. Boice is an able and clear expositor, making good sense and application of the text. Sometimes he spiritualizes or simplifies a bit too much. But I've learned much about simplicity of application from him, and we often miss a spiritual point lurking in the text.
I believe these are manuscripts of his sermons, and are accessible to the layman. If you are looking to study Scripture in depth, I highly recommend it.