730- You get a larger 4.7inch display with a slightly lower ppi, but it is still sharp, has better blacks and is a more modern spacious size. You will also gain Lumia Camera 5, so youll be able to enjoy dynamic flash, rich capture, living images, and more. Your also keeping a similar design as this phone shares a very similar build to the 920, while being slimmer and taller. You also lose some megapixels. No 4k recording in Lumia camera 5
830-You gain a larger 5inch display, lower ppi but still sharp. Also you gain a quad core processor, thatll be somewhat faster in just a few situations. You also gain a higher 10 megapixel shooter with a sixth element lens for sharper photos. You gain a louder speaker, and an aluminum band design with swappable polycarbonate backs, and also microSd expansion and a removable battery. Lastly you gain Lumia Camera 5 and its features except 4k recording
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930-You gain a larger sharper 5inch display with better blacks. You gain a much faster processor, the benefits of Lumia camera 5 listed under the 730, an aluminum band design with colorful polycarbonate backs. You gain a larger 20 megapixel camera that can shoot in 4k, and you gain the ability to activate cortan without touching the phone, by simply uttering the words "hey cortana".. But No Glance and no LTE in the U.Sunless you use the ICON on verizon
1520-All the same benefits of the 930, except with the 1520 you gain a larger 6 inch display (very large), a micro sd slot, and a much larger long lasting battery, and glance and lte in the u.s
HTC ONE M8- I don't know much about this device other than the camera will be worse, but the phone will overrall be faster, the screen will be sharper, and it has a premium metallic build with micro sd expansion, and better battery life. also a larger 5 inch display
Samsung ATIV SE-Also don't know much about this device other than it has a faster processor and a sharper screen that is bigger (5 inches). I do know it has a larger 13 megapixel camera