I had high hopes for GoPro Quik for Mac and waited patiently for a long time. Unfortunatelly it's not for me...
Quik for iPhone was not very fast, but at least it worked. Quik for Mac is the worst. Every change takes a minute to minutes. And if you change too much before saving the app crashes and you can start over again. According to the App Store my Macbook should be compatible, but it just doesn't work. I have the feeling that the problem is that every little change makes Quik change the entire video. It might be a solution to let someone make a couple of changes before adding these changes to the entire video, e.g. by pressing an "Apply changes" button...
Also weird: If you don't download the media to your computer you get an error stating "Unable to preview media" (which I get, the Cloud could be slower then directly from your hard drive); but you can't choose media from your hard drive. So first you have to upload your media to your GoPro Cloud. Then you have to download it from the cloud and after that you should be able to edit. Why not choose media from your HD?
I'm going to use Quik for iPhone again for now...