I've been on RSR twice in the daytime. The first time I thought...meh. Second time was a little better.
My issues are...
1. When the ride starts the music queues up. No transition, Indy has the choose your destiny, SM has the countdown, Screamin even has a countdown, ToT has the opening sequence. With RSR you just jump into it, no build up.
2. Along with the music when you enter the portion with the waterfall again no transition. You go from this catchy driving music to an epic score. Just seems like it jumps.
3. As mentioned before the idea of going through RS doesn't make much sense after you just walked it.
4. Dark ride portion the audio is hard to hear and with the race.
5. Ending is fairly anti climatic. Would have been neat to have Luigi and Guido at the finish line waving flags.