Okay I'll bite.
The RPO (Run-Pass-Option) concept isn't really a "system" in the same way that, say, the West Coast Offense is. Rather, it's a series of plays designed to give the QB the option to change the given play to a run or pass depending on what he sees from the defense.
For example, if the defense starts crowding the box to take away the run, the QB can pull the ball out and hit a WR on a quick slant, hitch, or screen. If the defense starts loosening up, he can simply hand the ball off OR take off running himself. This doesn't mean the QB has to run, or that it's by definition a "read-option" concept - though that is one element of it.
The advantage of the RPO concept is that, in theory, the QB has less to think about post-snap. He reads the defense at the line, makes a decision, and goes with it. Less thinking, quicker passes, ball is out quickly, etc. However if the timing gets disrupted, the QB makes the wrong read, or the defense starts disguising things, it gets messy. Further, the RPO isn't necessarily something to rely on all game long. Again, it's a set of plays, not really a "scheme." At some point the QB needs to play a 5- 7-step drop game, work the seams, etc. It also limits some of the run game concepts. Therefore sometimes the RPO can work AGAINST the overall rhythm of playcalling.
With the right QB, in the right situations, I really like using RPO to confuse and loosen up a defense. Particularly one that likes to crowd the box and take away the run first. Come out running some RPO, get the LBs on their heels, then either run power or pass over the top when they get caught peeking.
My .02