Here is where the Lumia 830 offers more than the Lumia 920:
"Expandable storage with micro SD (up to 128 GB)
"Removable back cover and battery
"Larger display (5-inch versus 4.5)
"Slightly higher megapixel count, better for cropping images
"35 grams lighter than the Lumia 920
"2 mm thinner than the Lumia 920
"200 more mAh in the battery (2200 versus 2000 for the Lumia 920)
"SensorCore support
"Newer chipset/more likely to get new features
"Dolby Digital 5.1 audio recording; better microphone placement on the rear
"Equalizer works with rear speaker in addition to headphones
"Brightness Profile for setting default display level
"Maybe faster at loading large, graphic intensive games http://wpcentral.com.feedsportal.com/c/33999/f/616880/s/3f92450
