I am not completely familiar with Virtual Sound Stage, and as I know how much work goes into making products like this, I don't like to directly point out any perceived weaknesses of competitive products. Indeed these guys seem to do nice work, and they even recommend pairing their product with our algo verbs such as Aether/B2 to supply tails, so I have a mutual respect for their work. I believe Virtual Sound Stage is primarily a gain panner with a built-in Early Reflections engine, but I am not 100% sure, so don't quote me.
Our system changes the direct sound itself providing instantaneous audio source width, uses several psychoacoustic techniques related to those discussed in this thread to achieve positioning, offers as much mono-compatabilty as you like/need via three different algorithm modes and control over various positioning rules, and is modulated to give additional life and organic feeling to the result.
Our system is furthermore capable of inter-plugin communication between Precedence and Breeze 2.5, where position information in Precedence is communicated to a linked instance of the reverb engine, and the entire DSP settings of the reverb engine updates in response to position. This creates something like an algorithmic Multiple Impulse Response system. There is infinite variation in Precedence and Breeze 2.5 depending on position, and both are modulated. Combined they create an incredible sense of depth and positioning. It's truly next level!
It's almost like when Spitfire or other library company records in Air studio and offeres 20 different mic positions or similar, and sometimes in situ positional variations. Our system can take a completely dry library, or physically modeled instrument like Sample Modeling, or real recording from your studio, and do the same, but not with 20 or so positions -- literally infinite.
And it also has the ability to work well with and compliment libraries that are already room-y, as we are very well aware some great libraries are recorded with lots of room-sound. We have various input modes to address this and help blend wet libraries with dry libraries.
Furthermore, the new Precedence 1.5, offers Multi-Instnace Editing, and Edit Groups! Not only can you see 10, 50, 100, 200 instances within a single plug-in GUI, but you can also EDIT them! Changing instance selection within a shared GUI is MUCH, MUCH faster than constantly having to switch between the DAW mixer and many plug-in instances! The linked Reverb Engine can be have instance selection controlled by Precedence as well, so you can keep one GUI editor open for both a and quickly control many instances with the same connivence as controlling one!
Finally parameters in both Precedence and Breeze 2.5 can be changed en masse for the entire Edit Group! So you can load preset changes for the entire group with a single click! Position information is retained! You can metaphorically simply transport your mix from Air, to Boston hall or whatever else you like by changing the preset in Breeze for the entire group. While retaining the relative in-situ positions! Or you can change the Alg Mode in Precedence between Beta and Mu and export two different mixes, the later with enhanced mono-comatabiliy if that is a critical concern. Or change the Delta and Loss Parameters to change the positioning rules for the entire group, and create macro-changes to "spatial contrast" for the entire group.
etc etc. but I will stop bc this starts to sound salesman-y.
we hope to have videos ready shortly to explain this all better, but the manual is arleady online with full details. Hope it helps.