thanks James, I tried to download the Live Arranger demo weeks ago from the US website but could not figure out how to do it....it kept asking to register.

Just click on this link.

I tried Live Styler a few months ago, found it really difficult to figure out and I found it's numerous numerical fields a turn-off, didn't like it.

Same here. It works very well but it's dog ugly looking software.

I think I like Live Arranger much better, but how would I be able to edit complete arrangements? It does not have any editing options such as punch in-out, etc

You would really need to download it and see if it has what you need. I'm not using my keyboard as an arranger at all.

Liosntracs also have their own Qranger program which is extremely deep. There is a developer currently making styles for it right now too. So you have plenty options.

also, how would I be able to see scores displayed on the Liontracs screen, a' la Yamaha PSR ?

I know it has this function but I haven't even tried it. I did load it up once, but never bothered to explore how easy it is to use and so on.... So leave that one with me and I'll get back to you.

Even if it doesn't do what you want, remember it's an open keyboard we are talking about. You can install whatever you want on it and there are plenty of programs out there for displaying sheet music.