Compare Mobile Phones Side-by-Side

The Apple iPhone Duo looks like the stronger device here by a fairly wide margin. Its much larger 7.6-inch display, 12GB of RAM, and 5000mAh battery make it the more serious choice for multitasking, media, gaming, and long daily use. The 120Hz refresh rate is already smooth enough that the Energizer’s 144Hz advantage is unlikely to outweigh the rest of the hardware gap for most people.

The Energizer Ultimate U660S does have a more manageable 6.67-inch screen and a higher refresh rate, so it may appeal if you prefer a smaller phone and care mainly about screen fluidity. But with half the RAM and a much smaller 3400mAh battery, it feels less prepared for heavier use.

Unless size is your main concern, the iPhone Duo is the easier phone to recommend. It simply gives you more room, more memory, and more battery headroom.