BobF
I'm getting the idea that no matter which you go with this, you end up with a lot of painstaking fiddly details to tweak in order to get articulations to sound correctly.
Yep. And I am not a person who particularly enjoys fiddling with details like that. Finale, with its Human Playback, gets about 97% of the articulations and rhythms to sound acceptable for my purposes. In theory, I could twiddle with the remainder at the MIDI manipulation level in Finale, but I'd surely go insane. Sonar is much better for that level of editing.
BobF
You have way more patience than me!
I have never produced anything that I would say is "fully realistic". I don't have that kind of patience. My main goal is for the playback to be good enough that the client will be happy, will want to perform the music, and will really get the musical concept.
I finished an arrangement last week for a big band. I did this entirely in Finale (no transfer to Sonar). There were two big flaws and a bunch of little things I would have changed in Sonar, but I just didn't have the extra three hours to go through that tedious process. One was a ritard that was way too slow. In theory I could have modified this timing in Finale, but I had already had some serious strangeness in the playback tempos on this file and didn't want to chance that. That was so obvious I thought I could easily explain that. The other big problem was one measure where Finale, in its wisdom, decided to interpret a rhythm completely wrong. I didn't figure that would be so evident, so I didn't mention it. Sure enough, after I played it for the band, the alto say player said "In measure 74, do you really want beat four to be late like that?" Grrrrrr. It shouldn't be this hard. But I was impressed she caught it. I guess that means that my efforts toward a decent playback were mostly worthwhile.
These two specific problems are things that could be considered Finale errors or weaknesses, so I am not blaming Sonar. But if there were a more integrated solution, I could easily fix these things in Sonar. And while I was in Sonar, I'd make a bunch of other refinements for a really polished presentation.