I've been using the 2-part Divine Liturgy book for a few years now, which I really love, but in this new edition, they fixed a couple of things that were difficult to reconcile with any church I sang in, e.g. "both now and ever".
There's just so many beautiful settings that sound great as a solo chanter, but when you have a quartet of competent musicians (rare in some cases... ha!) the possibilities open up quite a bit.
A note about the new printing: the cover is a slightly nicer shade of blue, and has a slightly grippier texture. Not sure if that's a good or bad thing, but time will tell. The new STM Press logo is quite lovely. I hope that sticks around for the long term. I also appreciate that in the Divine Liturgy book, they maintained many of the ornaments and details from Orthodox Arts Journal's website, though I wish this had been done in the Vespers book. The ornamental details are a bit Spartan in the latter. (I'm specifically referring to the small images that go at the end of a larger section.)
I purchased these (5 each), as well as the Great Vespers books, as part of the curriculum for a youth choir, where they will (God willing) learn how to sing in two, three, and four parts from this notation. I hope this proves to be very effective. Thank you for all of your work!