Is there a ROM for our phones that has some of the major features from the S5 like the power saving mode or some of the other stuff? Or even a full on port even though I heard that the ROM size if pretty hefty?
A true port would be difficult, due to the hardware differences. In any case, I'm not aware of a ROM like that, YET, but MOAR is being updated to KitKat, and when ready should contain a lot of S5 features, including power saving mode. See post # 7267 here: