I like VX. It's a challenge to understand. The modeling technique, being a hybrid like it is, is unique compared to a pure parametric modeler like Alibre or a pure explicit modeler like Rhino or SpaceClaim. I ran a demo of VX for a project that Alibre wasn't able to do. VX gave me a lot of great support during that demo period to try to get the example completed.
I'm tempted to pick up VX Innovator just to have the tool in my toolbox. Then again, to make it worth it, I'd have to pick up the Designer package because I have Alibre Expert now. I'd need sheet metal and the advanced 3D modeling of the Designer package. Also, Alibre does all prismatic features that I need in most of my designs. Beyond that, and I need the free form surface modeler of the Designer package.
Here's a better way to break it down.
Alibre Design Standard is equivalent to VX Innovator. Alibre Design Std is currently $99, VX Innovator is $199. After these promotions, then they are the same cost ($999 or $995, close enough).
If I learn the parametric method of Alibre, my transition to other history based parametric modelers will be easier.
If I need to upgrade, Alibre is less expensive to get to Expert than to get Innovator to Designer, but Designer allows for hybrid (free form surface) modeling in addition to solid modeling.
VX also integrates with their own CAM package much better than an Alibre bolt-on solution.
Where do you see yourself going?