The Nexus 7 is nice except for three drawbacks that I can see:
-- No HDMI out.
-- No external SD card slot.
-- No USB host, I don't think (so can't hook a USB drive or thumb-drive to it either as far as augmenting content capability).
-- No rear camera (though most folks aren't going to do a lot of pic-taking and movie-shooting with a 7-inch tab, probably).
Three out of those four are eliminated with the Acer Iconia A100 7-inch. It has a microSD card slot, a decent rear camera, and an HDMI output port.
The Acer runs Ice Cream Sandwich (Android 4.0), so if you really want Jellybean (4.1), that would be an advantage of the Nexus 7. The Nexus 7 also has a higher resolution screen.
The Acer A100 does not have USB host, which sucks, but at least you can jam in a 32 GB microSD card for ~30 bucks. That's a fair amount of content.
I'm not sure why so many reviews slam the Nexus 7 for only having 8 GB of internal storage. A lot of tablets only have that much, and most games do NOT utilize the external SD card anyway (that is up to the app designers, most Android installations can't do anything about it at the OS level if games want to store 750 MB internally).
I have an Acer Iconia A100 (8 GB), and have enjoyed it a lot. It is very good for acting as a multimedia kiosk by installing BubblePNP (can stream from any DLNA server) and using the HDMI output to stream to an HD TV. Also is a nice little game machine (though the Nexus has a faster processor and better screen, as I mention.) The Nexus 7 does NOT have an HDMI output port, as far as I can tell. I think Google wants folks to buy a Nexus Q for that, which is a pretty lame move on their part.
One last thing: battery life... The Nexus 7 has great battery life, the Acer not so much. If I were to play Angry Birds continuously (i.e. screen on), I might deplete the battery in just 3-4 hours. I fixed that by buying an extra AC adapter for work, so I don't really have to worry about power.
If lack of external space, rear camera, and HDMI output don't bother you, the Nexus 7 is extremely hard to beat at that 199 price. You can potentially grab an Acer Iconia A100 at places like Best Buy:
within your aforementioned budget.
Hope this helps...