To all who care:
For other reasons, I had recently had discussions with Delorme and Garmin techs. The impression I was given is that Street Atlas will continue, but the yearly upgrade is being help up for the addition of something that they would not comment about. (We can hope it is broader compatibility.) While I can export a route to a Garmin Nuvi, it is hardly a simple operation.
I outgrew S&T some years back. Yes, SA can be difficult, but higher performance often makes for greater required skill. We use it with everything we can. We get overlays from Discovery Owner's, POI Factory and information from Allstays and RV Park Reviews. I regularly plan 4~5K mile, 3~4 week excursions.
For all of my careful planning, I still have never had the plan for a major excursion be good at the evening of the third road day.
Matt