I haven't needed to go from Sonar to Finale in a while, so I thought I'd play with it last night before piping in...
So I tried it last night, and it works quite well. I am using Sonar X3c and Finale 2010 (soon to upgrade to 2014).
There are a couple things that MusicXML does not handle well, and you have to be aware of them. The one that always gets me is time signature changes. If you insert multiple time signature changes they may be ignored. I know that this has been discussed on various MusicXML forums, but it has not yet been resolved.
So what is the big deal? Why doesn't Sonar just do something about all this?
1) the number of Sonar users that read/write notation is small, the number that use it is even smaller. This applies to musicians in general, but I point out the Sonar connection just to be thorough<G>
2) MIDI and notation are not equal... not even close really. Standard notation is a means of conveying a musical idea to a musician. MIDI is a way of recording and playing a musical performance. They are not the same!
I have played around with conversion between MIDI and notation - both directions - since the days of Dr. T's Copyist and KCS. I have a pretty good idea - I think - of what is needed, but I'm not sure that the cure is any better than the symptoms... and I do not have the chops to implement it anyway (I do have a PERL prototype somewhere, but it was ugly!)
What is needed is a rule set that is user manageable. There needs to be a way to define the beats - there are way more ticks in a measure than beats, so you have to be able to say that a note is a quarter note if it starts in this range of ticks, and lasts for this range of ticks. Yes - it seems like the current crop of quantizing tools ought to do the trick, and in fact if you are willing to work hard enough you can get some great results that way, but it is slow. Slower, I think, than cleaning up the score in Finale.
And of course the rule set has to go both ways. I think that's the intent of Human Playback in Finale, and in some limited number of cases it can work well, but the number of cases is pretty small yet.
My solution, for now, is to try to make only one conversion in each direction.
If I start in Finale then I can either export to MIDI and import into Sonar (which works quite well, except for that overly quantized bit) - or I can print out the parts and play them in. This later approach sounds better by far, but my keyboard skills are not always up to the task. In either case, I can then tweak to my heart's content in Sonar until I end up with a PERFORMANCE that sounds great. At which point I may, or may not, need to export to XML and re-import back into Finale. Sometimes, (not often) the changes I made in Sonar are so insignificant that I can skip this step. Wish it happened more often!!!
If I start in Sonar then I only need that Sonar to Finale step... but I am still so much more comfortable thinking in standard notation that I usually start in Finale.
I would love it if Staff view was on a par with Finale, even if only for note entry. But I don't think that's a particularly good use of resources, so I continue with my work flow and usually I do not grumble all that much<G>!