Well without Notation in MB3 there will be no extensive Notation Fixes freds on the MB forum.

I installed last night with no issues at first.  I first tried audio tracks and they worked great.  Then I added midi tracks, but that started crashing Mixbus after a few minutes, but then it got better like it was learning from the previous crashes.  However, I had one real head banging dilemma--I had the hardest time trying to figure out how to change the midi instrument in a track where midi was already installed.  It was clear when adding the midi track how to insert any instrument, but when I wanted to change the instrument for another one, I could not figure it out (at first).  So I read the manual, but that was no help at all.  In fact, the manual is anemic and insufficent; I would say that Harrison really needs to write a real manual that is more than a few pages long.  Finally, I learned to remove the instrument and to use the plugin manager to install an instrument on the already established midi track.  I know there is a learning curve, and I am willing to put the effort in.  Having worked with Sonar since its inception, and with Studio One for a couple year, I find Mixbus, well, different.  I love the console work flow, but the midi workflow seems strange, if not just different.
 
BTW, I honestly love the "character", that "Harrison sound", that this Mixbus gives to audio tracks.  They have that nailed down and absolutely have it right.  However, their newness to the midi instrument world shows in how they have documented it (or not) and how midi routing and instruments are added to tracks.  Perhaps this is a problem with Ardour as its platform; I do not know.  Still, it is nice to have midi as an option.  
 
Hopefully, a better manual will come, and the crashing will get less frequent, or some updates will arrive soon.  Just my 2 cents!
[[EDIT:  I need to make a correction.  I just found the pdf version of the Mixbus3 manual and it is 324 pages long.  So I apologize for misleading anyone.  The midi section (in my opinion) still needs a description of how to change instruments; it mentions how to load them when creating a midi track, but not how to change them.  Nevertheless, I was wrong about the length of the online manual; it is more than a few pages, actually 324 pages.  
Here is a link:  http://www.harrisonconsol...opic/about-this-manual]]