I prefer studio one because you can break out the various devices, e.g. mixer, timeline, midi editor, etc., into separate windows and it's midi editor is top notch. You can look at multiple tracks at once, overlayed and color coded. It helps, because I can see the tonic relationships and chord structure between the instrument tracks. Plus, when I run midi drums, I break each drum onto a separate track for mixing, so by overlaying them, I can see the whole kit in one window.

And it has a scratch pad to try stuff out without having to write it on the main timeline.