As a longtime Sonar user (came aboard in the late 90's, I wanted to share how I use Staff View, in light of a recent discussion about improving it.
First of all, I use SV almost exclusively. I also use Events and Track view some, but not PRV. My compositions are midi mockups, done just for fun. You could say I really am a notation composer, who uses Sonar instead of say Sibelius, because the sound is so much better.
So, how have I overcome the limitations of Sonar's SV? I make two versions of my works, a sound version and a print version. In the print version, I use standard abbreviations, like "tr....." to indicate a trill. (The sound version will of course have every note written out, so the abbreviation saves a of of space). For groupings like septuplets, I write in by hand after printing the score the proper notation. I put a bunch of other stuff in by hand as well.
One of the biggest limitations of the Sonar score when printed, is that every instrument is on every page, whether playing or not. This wastes a ton of space, and makes the score a lot longer than it should be. Now, to make the score more professional, I could physically scan it into a notation program, work on it there, and reprint it. I have not done this as of yet, as I only print the score so I have a hard copy of the music in addition to the music files. But you could do this as a way to produce at least semi-professional scores. Scanning the score into a notation program is thus a potential workaround in the absence of any other way to get it into notation software. But it would of course be so much easier if you could export it somehow directly. I don't really know what XML files are, but I see them mentioned a lot. Scanning may be a way to get around this at present.
The beauty of sonar is that there are so many ways to do things, so many wonderful tools at your disposal. and it is very intuitive. I have tried Cubase and Ableton, and don't care for them. Reaper has a reputation of not being intuitive. So I plan to stay with sonar. I may even upgrade at some point (currently using 8.5). My hope is that at some point Cakewalk will make some improvements to SV. but at least I have found I can use it effectively as it is. Hopefully this thread will help others do the same.