Yeah, the interface is unchanged. There is no search and you're limited to a few of the latest videos (I would guess around 30-40 per category.) My only other nag is that I sometimes have to quit to the home screen and re-open the app if I back out of a video and then try to resume play.
Streaming quality is good, and you have access to archived subscriber content. No access to live subsciber content though, as stated above.
I used to use the unofficial Justin.tv app for the free live shows, but that stopped working recently. I'll have to try the unofficial Twitch app to see if it makes a difference.