So many different options, ‘tis a minefield for the uninitiated, anyone got a pointer as to which option and why?
It's basically only three ,,, Planner, navigation, and planner with navigation. I have planner with navigation and they work very well as a pair.
If you use a Garmin or TomTom and are happy to carry on using those then just the planner. If you want nav on your phone, use, or intend to use, a carplay/android auto panel (or want phone as backup, use in the car etc.) then get both Planner and Nav Next. Using the Planner and Nav Next makes things easy as your routes are automatically available on both PC and phone. Navigation as planned is what the device will follow, as opposed to another GPS taking your route and changing it because it's routing algorithm varies from that of MRA... I used MRA Planner (Gold) with a Garmin Zumo 590 and then a Zumo XT for a few years, it worked very well, before switching to Nav Next.
I bought both and use the planner (gold lifetime) with my Garmin XT, I also bought the Nav next and use it on the phone and in the car. Earlier in the year I planned a load of routes when we visited Utah and downloaded the offline maps to use in the hire car which worked almost perfectly (the phone just got a bit hot)