In my personal opinion, if done right I'm all for a Power Rangers season being a direct translation of Sentai. Granted, originality is always a plus but sometimes the original material just doesn't fit right with the overall theme or whatever.
I do agree with Underachiever, Power Rangers is not Sentai nor should it ever be. But if a season has the right theme to where it can still be Power Rangers but follow in some Sentai light...go for it! Just as long as the writing is good, and the characters/actors add some of their own spice to the source.