Why the title? Well when Turbo was released, one of it's problems is that the writers couldn't agree on whether the season should be a dark, epic, serious story, or be light and comedic, following its Sentai more closely. The end result was a season that attempted to balance both and came off poorer for it.
RPM on the other hand, nails it down. I don't know if it's the writing, directing, acting or whatever else, but the truly fascinating thing about this season is that on one hand, it clearly has the darkest premise any Power Rangers season could ever have and yet, it has some truly off the wall humour that had tears of laughter running down my face to the point where I had to pause the opening of the episode "Ranger Blue", in order to catch my breath (and this is a guy who would sit through Bulk and Skull's antics with a stony face even as a kid).
The dark premise is also well handled. My favourite episode of the season (and the show over all) is "Dr K". An episode whose drama had me moved almost to tears one moment, and standing up and cheering for the rangers the next.
The interesting juxtaposition is that the show takes itself seriously, something that not every Power Rangers season seemed to do, and yet it somehow manages to poke fun at itself at the same time. The self awareness in particular is very nice, something that also worked well in Ninja Storm. But while they only pointed out old clichés in Ninja Storm, RPM goes a step further. Not only does it make fun of certain things we've come to take for granted in Power Rangers, but it also comes up with some surprisingly interesting and plausible (in a pseudo science sort of way) explanations for them. After many seasons of excessive, entirely unneccesary explosions, not only do the RPM rangers point out how silly it is, we actually get the explanation that the explosions are a way for the suits to discharge built up energy. The reason why the rangers have to shout out a morphing call is because the morphers have a voice lock (similar to the Quantum morpher) to prevent anyone else from using them.
Ultimately, this season had it all. Good actors, well written characters, great direction, well plotted story, gripping drama and yet some truly hilarious comedy. While Power Rangers may be going back to Saban, this is a perfect swan song for Disney's ownership of the title.