Before I sold my 2012 R3, I had Rotor 3D+ cranks with Q Rings. I guess I would say the difference isn't as revolutionary as advertised. I liked them fine enough, but I don't realy feel like it makes much of a difference for the average cyclist that is just trying to put in some miles for fun and fitness. Cycling is constantly marketing the "next best thing" like we see with cell phones or computers, etc. I ultimately had to find that space where I felt confident that I had what I needed and that my bike was more than enough for my purposes. In the end, I would say definitely try them before you spend the $500-700 it can take to get them and my guess is that you will probably end up thinking that they're cool, but not worth that kind of dough.
