Does anyone know anything about Video Enhancer 1.9.1?

Does it work?

current version is 1.9.3
and do not know what you really mean by "Does it work? "

Does it perform as advertised? How difficult is it to learn, and does it work inside Vegas 8?

It does exactly what it says, and sometime it is a life saver. I use only the virtualdub plugin version so i cannot say for other apps. It is very simple to use since all is almost automatic. For sure you can drive it in manual mode, but i never had to fiddle with manual mode to find a good setting.

Basically it ask you to define a part of the picture that as a uniform zone.
It is ok to shoot the ceiling or anything "flat" surface sometime to get a workable frame to help the process. if you do not get it, it still works, but the settings choosen won't be the best. risks are that filter is too heavy and you loose details and get a "soft" picture.

If you shoot in low light it is the best plugin you can dream of.
Apply before anything else for best results.