I shoot with NV most nights of the year. I use an NV spotter or a mini thermal to find my fox, then shoot it with the dedicated NV riflescope on my .22-250. I had my 161st fox of the year last night, so I must be doing something right!
With regard to eye black-out - that is very common with cheap NV systems. The decent ones have manual gain control which allows you to turn the tube brightness right down. If that option isn't available, then just get some red film and put it over the eyepiece.
I have to disagree, my NV units range from the £99 lidle spotter,Merlin Cobra add on, Yukon Ranger Pro spotter, 4x50 Gen2, and a 5x50 Gen2+ dog danglies and they all have the "black eye effect" so price doesn,t really come into it.
Regards WB