I moved to Boise with my family 7 years ago. We've lived in just about every part of the country, and this is by far the best place we've ever lived. The cultural organizations are surprisingly excellent, the recreation opportunities are unparalleled and the general quality of life is 'way above average.
There are drawbacks: we are liberals in a state which is very conservative, although Boise is more mainsteam. Housing prices have really escalated since we moved here, so homes aren't the bargain they once were. Salaries tend to skew below average in most professions. The school systems are a bit above average, but the physical plants of many are pretty tired.
I'm not that far away from retirement now, and we plan to stay here "for the duration." We've lived in Minnesota, Florida, Texas, California, Virginia and Massachusetts, and Idaho tops them all!