For me applications launch a bit faster than on J1, most dramatic speed up is for launching camera. Of course it's hard to say if it's because of the OS version, as my J1 is on older version. Overall I'm very pleased with Jolla C and it is definite improvement compared to J1 for my use cases. I can't comment on battery as I have not had enough experience. My gut feeling is that it's at least as good as on J1. For improving performance, you might want to try setting governor to performance as per this post: http://talk.maemo.org/showpost.php?p...&postcount=742 With that, I notice performance improvement in many parts of the UI and haven't noticed battery drainage due to it.