But what does that extra $30 get you? Well, more. And less.
The Iconia Tab and Nexus 7 both feature Nvidia's quad-core Tegra 3 processor, both have 8GB of built in storage, and both run the latest version of Android (Jelly Bean, a.k.a. Android 4.1). The Iconia has some very nice features that the Nexus 7 lacks, however, most notably, a Micro SD card slot so you can boost the device's storage capacity an additional 32 gigs. It also has a micro HDMI port, so you can watch your movies/play your games on a full-sized TV. Very nice.
The biggest disadvantage is the screen. The seven-inch Iconia Tab A110 only has a resolution of 1024 x 600 which makes for a rather paltry pixel density of 170 PPI. The Nexus 7 crams 800 x 1280 pixels into those same seven inches, bringing the pixel density up to 216 PPI. Considering that reading and watching videos are likely to be the main things you do with a tablet this size, that might just be a deal-breaker. The Nexus is also about 1.75 ounces lighter than the Iconia, and it's a bit thinner, too. More here.