Good Sam Club is mainly a social organization of campers who like to attend group events, either from a local chapter with 10-20 rigs that meets monthly, to annual state rallies, to occasional national rallies.
Some of the additional benefits, such as this forum, are funded and supported by the combination of sales at Camping World stores/on-line (co-owned by the same company as Good Sam) and membership sales by folks hoping to get some additional benefits.
Good Sam lends it name to a nationwide roadside assistance program. It can be a very useful program, but there are competitors.
Good Sam lends its name to a company specializing in RV focused insurance. Another company focuses on 'extended warranty' programs.
Many folks have a very mistaken impression that Good Sam runs campgrounds. They don't. Campgrounds offer a discount averaging 10% off each night's RV spot rental in return to being listed on the Good Sam web site.
Good Sam members also get discounted prices at Camping World on retail store items.
For most folks the priority is discounts on camping spots.
The next 'benefit' would be discounts at Camping World.
The next item on some lists would the social aspects of the state and chapter groups.
I've really never used the trip planner. We are full-timers and have traveled over 36,000 miles with our current trailer over the past four years. I have a planning method I like, and it works for me.
The Good Sam Planner works about as well as any other tool. i.e. - the most important thing about using the Planner is to take the time to learn how the tool works, how to make it do what you want.
