We have used both Life Science and Earth and Space.
I really liked the way she provides a list of all materials required for the year, an outline of the program that highlights the big and small ideas covered, and very extensive correlated reading and website lists.
It is a very well organized program.
We enjoyed the Life Science better than the Earth and Space. The experiments were doable for a first grader and I felt he learned a lot.
We had a little more trouble with Earth and Space. With a lot of the weather experiments we couldn't get the "correct" results and they were hard for my young student. I ended up supplementing a lot with a Dinah Zeke book called Earth Science. I found R.E.A.L. Earth and Space to be more dry (as pp mentioned) - less hands-on, get dirty - than Life. We like "hands-on, get dirty" at my house.
HTH.