I have only used the VRtex360 and Soldamatic device during demos. I have used each of them 2 times.
I am by no means an expert on the topic but am somewhat interested.
Here are a couple of Lihnkedin posts that may be of help. This one is kinda long winded (I just get that way sometimes) https://www.linkedin.com/pulse/learning-weld-without-welding-gerald-austin
Another is from a friend who has multiple soldamatic units in his class. https://www.linkedin.com/pulse/training-welders-you-can-keep-heat-anthony-hardin
Lincoln also has a new lower cost and smaller unit called the vrtx mobile.
You mentioned price not being a factor. Consider that you can get 3 for the price of one. That seems like an important factor but I guess everyone has their own things that are important.
My most recent use of the Vrtex360 was after I wrote the post above. One major issue I had with a $50k piece of equipment was the fact that there was no diopter adjustment in the hood for near vision. I scored in the 40's using the hood. 89 without by just looking at the gun with the hood off while welding with no visual representation of the weld.
Note that the price on the vrtex has stayed very much the same since introduction to now. So either there hasn't been enough volume yet to pay for the "development" or something else.
I also have a realweld trainer. Though it has been useful in a couple of cases, I cannot see how it would ever pay for itself.
Though it doesn't have t he same "wow" factor. A washer on a table with a tig rig can be a pretty good muscle memory builder and thats really what its all about. The visual feedback in my opinion is only a small factor since it poorly matches the real thing.
I am working on an idea that can be attached to an electrode holder of any type and measure euler angles and retract a fake electrode at the same time. Its one step above the washer method but will use less than $200 worth of hardware.
I would suggest contacting both companies and asking for customer contact info where you could call and talk to some of their users about what they think. It seems welding instructors may be a quiet bunch when asked specific questions online about what they do.
Have a great day