New version does not work on iOS6
I think everything in the old app is in the new one and then some! Seems like more sound effects, you can also slow or speed up the video, freeze frame, new title effects, picture in picture etc...
Once you learn all the ins and outs, like swiping down to cut, it's amazingly easy to make a nice video and FAST!
I cut 3 videos together, added a title, added some still pictures with nice transitions and also added a picture in picture video. The video in the box had no sound, but when you tap on the added video that's on top, and click audio you can see it initially has the added video on mute, (a slash was through the audio icon), just clicked it off and adjusted the level a bit and worked perfectly.
It's very simple, but I can see without any instructions some people would not get the most out of, I figured it out fast without any help from the help file at all. But I would suggest anyone hit the question mark ? and select more help and then go through all the help, very nice addition.
I showed a friend how to rotate the video in the old iMovie and he was like gee wish I knew about that before

simply use 2 fingers and twist to the direction you want to rotate. Zooming in is a nice new feature, when you select the clip, it's a tiny magnifier you touch and then you can zoom in. Detaching audio from the clip is nice as well.
So I really like it on my first look, and super fast on my 5s, was amazed at just how fast it was. It's still amazing to me to be able to edit a 1080p video this fast on a phone.
Looked great on my Apple TV.