I understand the convenience of extended battery on the Maxx, but I have never had an issue with the battery on my Razr. A typical day, my phone is off the charger at 8AM (when I get to school or work) and it lasts until 9:30-10PM with anywhere from 5% to 40% battery depending on my day. I would guess my usage is pretty average. Heavy on facebook, browsing, and checking emails. I don't take a lot of pictures, and sporadically play puzzle games. I am also pretty evenly mixed between 4G and wifi. I received an external battery pack with my phone, and I keep it on me in case of emergencies, but have yet to need it.
Both prices are great, so I would think about your usage and decide if the standard battery will be sufficient (Razr) or if you will need more (Maxx).
Both prices are great, so I would think about your usage and decide if the standard battery will be sufficient (Razr) or if you will need more (Maxx).