I've been using Microsft Steets and Trips for my road trip planning since 2004, although I found some other tools easier to use for simple trips, and online route planners having more up to date information and sometimes better, or better targetted, point of interest information (e.g. Good Sam planner for RVing). I use S&T because I've found it easiest and fastest, for planning by iterative modification.
I like to find out a basic A to B, maybe with a few points of interest between, then find additional interesting places along the route, and go from beginning to end putting in stops and stp times, watching what happens to the rest of the trip. S&T is very good at working time into the travel plan, easily and quickly.
I also use DeLorme Topo and Street Atlas, often on a second computer, to acquire information along my route that is just not in S&T (terrain detail, public parks, an independent map database, etc). But Topo it is not a slick an iterative planning tool as S&T, Topo user interface is more complex because the software does so much more.
I am not familiar with Streets and Maps. Who sells it, I might look into it.