Interesting that you should ask this question at this time. I just finished reading both books.
I'm not going to give a break down by locus. Suffice to say that some are stronger than others. Although the text is heavily edited, the voice of the primary authors often comes through (e.g. Robert Kolb on election). I can't think of one that I didn't appreciate. I learned from all of them.
I found the "building blocks" approach a bit difficult to get used to at first, but as I progressed I found it quite helpful. I've been going over the Sacraments in my Adult Bible Class and I really appreciate their survey of Old Testament types and pictures. It brings the whole of Scripture together. I also liked the survey of the historical survey of various times and thinkers in the Church for each locus. The use of the building blocks seemed to be an attempt at bringing the whole of the theological disciplines to apply to each locus and, for the most part, I think it succeeds.
On the downside: why no index? Yes, I understand that Pieper didn't have one when his Dogmatics was released, but to release these two volumes without an index is indefensible.
Second, these two volumes definitely show the signs of being a political football in the LCMS. There is simply no other reason it should have taken 30 years for these two volumes to have been published. Sadly, many of the primary authors of various loci have passed away in the meantime.
Because of that, there are some deficiencies, e.g. in the locus on the Holy Spirit, there is a long discussion of the charismatic movement, which has pretty much burned out (even Assembly of God churches downplay it). There is a discussion of the Church Growth Movement, which has also petered out. There could be more on the emerging church movement and dialogue with those writers. I would also like to have seen more interaction with feminist and liberation theologies. There are some updates to some loci, but, at this point, I think there was a strong push just to get the volumes published.
I'm pretty sure that these will become the standard systematics texts at both seminaries, possibly used in conjunction with Pieper. I think they are overall very good. I just wish it hadn't taken 30 years to get them published.
