To have a battery that is 3,000 mAh or larger, this phone would most likely be 9 - 10 mm thick. I'm fine with that... but would not be fine with a small battery.
Thinner doesn't mean better in my book.
Myself: 2014 Kia Soul+, HTC Droid DNA, Motorola Droid Razr M, Nexus 7 (2013), multiple Google TVs
Wife and Kids: Motorola Moto X, Apple iPad 4th Gen, HTC Droid DNA, Nexus 7 (2013), Galaxy Player 4.0,
Retired: Galaxy Nexus, Thunderbolt, Droid Pro, Fascinate, Motorola Droid 1, 3 & 4, Transformer TF101, Galaxy Tab (7" WiFi), Archos 70