No HDMI input,
Seriously why do people say this is a con? It's so... obnoxious (no offense).
First off, no one is going to be using the monitor's speakers. It's like when reviews say X monitor is crap because of the speakers, even though the monitor itself is the best. It's just absurd. That's the main 'advantage' to HDMI.
Secondly, adaptors. Adaptors, adaptors, adaptors. They are like $1 on ebay, every monitor and graphics cards comes with adaptors anyways.
Who cares. Like you are seriously going to write off a $300 monitor that's $100+ reduced in price, because it doesn't have an HDMI input that is solved by a $5 adaptor? It's just so absurd.
Anyways, as a I understand, a lot of the Asus monitors have ghosting issues and quality control issues and way crappier stands. They are great if you want a budget 1080p monitor, like want to pay $100-150 and you just can't spend more at all, but the U2312HM, as I understand, is significantly higher quality (though I wonder if it's a huge leap, if it's even noticeable, I mean not everyone gets ghosting on the asus monitors, I'm not sure if it's because of poor QC that so many have it or just they ghost a lot and maybe some people don't notice it).
Also, I posed the thought the the U2412m is worse than the u2312hm with worse real-world input time or response time - apparently that's just according to a TFTCentral review, who isn't trustworthy with outdated measurements. Prad.De, apparently the only trustworthy monitor review site, says the U2412M is actually better than the U2312hm in quickness (i dont remember if they meant response time or input time).
Anyways I'd still go with the U2312HM because I play sc2, one of the few games that can only play in 1080p and 16:9 and just can't do 16:10 at all without stretching, bars, etc nastiness. Honestly I don't know if any game can do 16:10, and isn't all media like HD content in 16:9 anyways? So doesn't that mean 16:10 is only good for desktop, general usage? I'm sure it's better for something, just not for the usage I do.