Canorus is a very helpful tool for composers and rearrangers. It delivers great output with the lilypond backend. Currently though there are some speed issues for larger sheets to a score, especially when adding notes. I like the scripting possibilities but the developers have still to do quite a bit on documentation this feature. It's nice to see how the different views (help, (multiple) score, source, cli) integrate in the UI. Zoom with the scroll wheel works flawlessly. I'm really looking forward for being able to customize all the available function so I seldom need to use the mouse. I only once set a piece with a Midi keyboard (I cannot play piano/keyboard) and this worked without any problems.