The only thing I can think of which needs to be improved in the Gnome Software Center is that the app installation process really should be one step. Either that, or the install button shouldn’t say “Install” during the whole process - it’s frustratingly misleading.

It should at least say “Downloading” when it’s downloading, change to “Install’ once the download finishes, change to “Installing” when it’s installing the app, and then change one last time to “Installed” once the app is installed.

But for efficiency, you just can’t beat Synaptic!