Since first trying Ghost, one of the best things about editing my theme is the ability to host on Github. Through a simple integration I can easily edit my theme to make changes from almost anywhere. If you want to do this too, this guide should help you out.
I've just run through this guide myself, and the theme for this blog now automatically updates whenever I push changes to my repository. This is going to be so much better than using scp or sftp to manually upload changes.
Weirdly a lot of this was already "available". Albeit marked as being experimental. For example, I've been using the members feature and email newsletter feature for a few months, and I have an accent colour selected already.
The thing I'd like them to focus on next would be for a better mobile/tablet interface. I don't think we'll ever see a native app from them, seeing as they are a web company. But I'd settle for a website that's at least usable on an iPad.
I use Ghost to host this blog and my newsletter, so it's good to see someone else enjoying it. Jeff's experience seems to match up with mine, it's a great service, but it can still be improved in a few ways like he mentions.
One of the big reasons why I think I'll stick with Ghost is the member/newsletter support. Without that integration, I could imagine switching back to WordPress in the future. But for now, everything seems pretty good here.