The new 1.7 Firmware update for the PS4 added a new "Best HD" livestreaming quality for both Twitch TV and Ustream letting you livestream in 720p resolution.

Below you can see a screenshot comparison between the old "Best" and the new "Best HD" settings. In order to best see the difference, you can click on each picture to see it at full resolution and then flip between each tab.

The quality increase isn't massive due to the compression of the footage, but it's visible if you squint. You should also remember that the best option depends on the upstream bandwidth of your internet connection. If you have low bandwidth, you'll end up with extreme compression in motion with "Best HD" effectively lowering the quality of the stream.

Twitch "Best"TwitchBest

Twitch "Best HD"

TwitchBest

Ustream "Best"

UstreamBest

Ustream "Best HD"

UstreamBest

Below you can also find an animated GIF comparing all the four settings. As usual, you can click on it to see it at full resolution and start the animation.

PS4Stream