I liked that this book was explicitly geared to a senior audience, to people who may be thinking that "I'm too old to make changes." The target demographic is older than I am (I am early middle aged) but it was still refreshing to come at the challenge of new growth from a perspective that takes age into account.
The best part for me was the early chapters where he wrote about developing a mission. We've all heard about "mission statements" before, but Grandt goes beyond that to talk about detailed plans, expecting set-backs, going slow to be able to maintain momentum, etc.
The advice here is good for everyone, but if you're in your twenties or thirties you'll probably want to select a different motivational book. For 60's and older, this is what you want. For those of us in the middle, there's real value even if not all of it will be applicable.