Bruno,
If I understand this device correctly you would not reach anything with it in your situation.
This merely converts a real X-Y color signal and transforms it to a _raster_ VGA signal. In a way, it's exactly the reverse of a Zektor vector.
You can see that it's raster already on the Youtube video (which looks like they use shockingly poor dot-pitch CRT's too !).
To me, this takes the heart out of a vector game.
In your case, running that special vector mame version will be probably even looking better.
I see only one nice use for this device: you can use it to test vector boards on a regular test monitor that you may already have (although we usually use CGA monitors for checking of course).
But then again, I don't repair vector boards nor test them much. And it's pretty pricey.
On another note, but very SW / vector related, this looks interesting:
http://www.vimeo.com/2815795