mmm... interesting discussion.

About markers :
Diki, when you change the midifile position and go to one marker, program changes, volume, expression... and every thing are OK
I had to work hard for that, but now every thing is perfect.
The markers are displayed on the screen, with their name, So if you select for example VERSE while midifile is playing, it will wait for the end of the bar, and will go to the verse position. You don't hear any glitches, everything is perfect and on time !
vArranger can display 15 markers on screen, and use the arrangers variations buttons to navigate through the markers, but you can have more and assign 2 buttons to next marker / prev marker.

About VSTi :
From the begging with vArranger, I wanted to separate the style engine and the sound engine.
Diki is right, it's not easy to accommodate all styles from different manufacturer with all sound modules. But this is MY problem, not the user problem.
I am every time working to improve the sound quality in each versions, and vArranger users don't have to bother about anything. Just load styles and play.
Now, tons of musicians are asking me about having a 100% software solution. I understand that it is cool. It's for me a bonus for vArranger to be able to switch from external hardware modules to internal well know soundset. I am working on it with some humility. I still don't think that in a near future I will gig with a VSTi based vArranger. I don't think that I will do better than Yamaha Roland Ketron and Korg who have some millions dollars to spend on R&D.
But for sure I have something to bring to the arranger music world.

As midem said, I have not set my goal to win the war against hardware arrangers, that I still use and love, but to add another working solution into the musician pocket.