I am using motion/R&G very often, and i have some experience with Princeton, but i dont consider my self master of it.
So we have a slow/fast/and a very slow kind of outside focus offenses. Motion is really good when you have good offensive flow, and is giving lots of shots to SF/PF if they can shoot well from outside. Since they are looking for the best shot available, (the same goes to every slow tactic), passing is really important, and makes the JR less important, since if a player cant take the long 3, will not take it.
If you chose to run, then HA/DR/JR are more needed, since the players should create there own shots than wait from the others to do it. With the proper personnel i prefer motion without 2nd thought. If you dont have it, both offenses tend to look very similar.
Princeton: It makes the big men more important, passing as well from every position. Do your big men have very good outside skills+passing? If not dont even consider it. In my book is the most complex offense of the game.
To sum up, there is not a clear answer here, its all about how your team is built. I hope my small analysis will help you to get the best decision.