I've had some people ask what I think of New Child Montessori. Here's my initial thoughts, keeping in mind that we haven't started Montessori time yet. :)
I think it's a fabulous purchase if you're looking for a bit more structure than traditional Montessori; it strikes me as a Montessori way of doing unit studies. I like that it brings in topics that don't fall into the core areas -- like animals and plants, history, space, etc.
We're not following it page by page. First off, there's too many things to do in just one year! Secondly, there are some things I want to focus on and others I want to drop until Nugget is a bit older. Thirdly, I needed to change the timing of things -- in Florida, it's best to do animals and plants in the fall and winter when we can be outside, and save the continent studies for when we're stuck inside in the summer.
I started by writing out the New Child plan for a year, then moving and altering as necessary to get a personalized overview of what I'd like to cover. I use the book lists and activity ideas, and may pick up on some of the songs/rhymes/etc.
So for me, it's more of a reference set than a day-by-day plan. I think it would work equally well either way.
I don't have any experience with the Supplement, Art Guides, or Yoga (although I totally covet the Art :) -- maybe another year!). But the seasonal guides are well-written, well organized, and generally an amazing amount of material for the price. I highly recommend them, and wish I'd gotten them sooner.