Our tests didn't reveal world-beating picture quality, but the 640U does offer accurate color and a matte screen--the latter especially important in rooms where ambient light control is an issue. Its weaknesses, namely lighter black levels and less-than-perfect uniformity, leave the door wide open for competing plasmas to score higher, but I have a feeling that Sharp's ultra-aggressive pricing, and the mass-market appeal of LED/LCD, will guarantee the 640U its own sweet spot among the most popular big-screen TVs of 2012.
If you're comparing by content, Sharp falls short of most major-name competitors, missing Hulu Plus, Amazon Instant, and even Pandora and Napster (the latter two were available on 2011 Sharps). Its interface is simple enough, consisting of a launcher strip across the bottom of the screen. Higher-end models get a "full-screen" interface option and a Web browser.