Is your 2013 Moto X broken? If not, why replace it? Is it more up-to-date software you want? If so, go for one of the alternative Android distributions (eg. Cyanogenmod: https://wiki.cyanogenmod.org/w/Ghost_Info). Is the battery bad? That can be replaced. Is it not fast enough? It might be with an alternative Android distribution on it. That phone is only 3 years old so it does not sound like it is in dire need of replacement (if it isn't broken to begin with, of course). I still use a 2011 Motorola Defy, others use devices of similar age. If it still works fine why replace it?