For those sporting the AT&T Nokia Lumia 820, check your settings because an update is available for your Windows Phone.
The latest software update is SW 1232.5962.1314.001 and includes improvements to the automatic display brightness, a fix for intermittent screen blanking during calls, connectivity improvements and a hand full of performance/stability tweaks.
If you haven't seen the "an update is available" alert, just go to your Lumia 820's settings and choose phone update.
For those who've updated their Lumia 820 Windows Phones, let us know in the comments if you've seen improved performance.
Source: Nokia; Thanks, everyone, for the tip!