FWIW, I've tried RVParky, RV Trip Wizard, Furkot, Roadtrippers and some others but still always end up coming back to Googlemaps coupled with a hard copy mapbook and my spreadsheet of the trip.
Generally speaking I detail all the places, near our route to the decided end destination, that over the years I've accumulated on a spreadsheet from research/readings/blogs/forums etc. Then I'll look at distances and depending on what it is we want to see/do decide whether it's an hour or two down the road and a one or two or more overnight stop or just a lunch stop and a couple hours or whatever. We leave quite a bit of wiggle room in our travels so if we arrive somewhere and enjoy it wanting to stay a day or two longer we can. Likewise some places we move on from faster so it all evens out at the end of the day we find.
With google maps it shows you the times and distances from your last POI to the next = simple. Also remember there's "my maps" as well in google and the option to layer.
What I've found with the various trip planners is that some don't make it easy to put in Overnight stops for recalculating, sometimes when you drag and change a stop from their predetermined route, when you add more in it messes it up, some are too restrictive on the number of stops max you can put in, and various other issues. Seems like each and every trip planner has some quirky thing or another that's not compatible for us.
Like all things nowadays, as RVers we can end up with information overload on choices for research. For us once we've decided where we are headed and what places we want to visit enroute its: Hard copy map book, googlemaps, free campsites.net, casino camper, Ultimatecampgrounds, sanidumps and gas buddy for the most part. For those needing info on particular CGs, I'd definitely check them out on RVParkreviews as well for overall feedback.
We are aware of many other resources but rarely use them unless for example looking for boondocking areas in Florida we'd look at the WMAs.
Everyone travels differently and has different levels of importance. For some the CGs/RV Resorts are of paramount importance on facilities, accessibility etc. For others it's something else that's more important such as fishing/kayaking/hiking/nature/quiet/dark skies/something else. For us we are totally off-grid independent and have no interest at this juncture in our lives of what's available at a specific resort/CG. In years to come that may change but for now .......
Happy Travels.
It Takes No More Effort To Aim High Than To Aim Low - Reach For The Stars