I'm a recent vMix convert, and while I'm enjoying the software a lot, of course I'd like also some more features to be added :

Generally speaking :
-Keying : a bit more control on edge feathering and key shrink/grow.

For virtual set building :
- Automatic thumbnail creation when you create your own.

- spherical virtual sets (aka holographic sets in tricaster) : it's basically a spherical map (360°) projected on a sphere. It allows for more dramatic and realistic panoramic shots. It's a bit more complicated to create, but with a 3D software or camera stitching software, it's doable.

For Virtual set control :

- add a virtual joystick to pan-tilt-zoom in the virtual set on the fly (not only preset shots)

- and/or allow to plug in a real joystick or midi device (knobs? faders?) to physically control ptz in virtual set

- Allow a dedicated monitor/window for another operator to control the virtual cameras on the fly, while the switcher is doing its stuff

- add a virtual joystick to pan-tilt-zoom real life PTZ cameras from within vMix

- and/or allow to use the real life PTZ cameras inputs/data to drive virtual ptz in virtual set.

Best,
Eric