I have just just made some experience with my new spark. There are two issues which seems form me very important for the live performence.
1. A smooth (re)load of a new/or the current sound kit. Not only for loading another kit seamlessly, it can be used also to reload the current kit. (in case you overdo with some parameter setings)
2. The ability to copy/paste single step-tracks from a project to another. (with the option of choose with/without automation)
i think this two improvement where already mentioned by other users. I hope the further updates will include it.