How have you implemented the VCAs into your workflow?
Are you changing to VCAs instead of Group Tracks/Busses entirely? Or a combination (won’t that be messy quite fast)?
Just thinking out loud I guess 
I am only playing with VCAs because I don’t yet trust them in Cubase for anything else but tests, plus, I am too used to tweaking faders with the mouse wheel, which is a nono for VCAs as of 8.5.1 
That being said, I am sure they’ll find their way into my templates once properly implemented (should that ever happen), but not as a replacement for busses.
Here’s a typical example:
acoustic guitars + inserts (no sends) —> acoustics bus + inserts + sends
electric guitars + inserts (no sends) —> electrics bus + inserts + sends
solo guitar + inserts + sends —> Stereo Out
Both busses together with the solo guitar are VCA-linked to a guitarsVCA.
This way the sends are inline with any volume changes, and the VCA allows me to control their volume, mute and solo.
It’s an interesting topic, let’s keep this alive.
I think it has useful applications when working on a project with video and you have sound design and music in the same project.
Useful to alter the volumes of the sound design vs the music without bussing everything.