Good questions.

Any dedicated NV rifle scope is made for this reason with large objectives lenses and is a stand alone system.  Their NV views overall are the best in their class in relation to the Raptor and even the D740/760.  

With that said PVS-22's as you know are "clip-on" devices that rely on the quality of day optic glass looking through them.  Now a true comparison between using a clip on out in front of S&B, NightForce, etc. at 4x and 6x in the same lighting condition vs. a Raptor 4x/6x will render an image very close but the Raptor will win out with a bit better contrast and resolution. NOT by much, but still a bit better.  In extreme dark conditions dedicated rifle scopes also will perform better overall.  

Of course the beauty of the PVS-22 is you can bring up the magnification of your day scope where you cannot with the Raptors. Your fixed at 4x/6x. This magnification will be dependent on your lighting conditions. We find a good sweet spot without intro to IR light is at 8x with the 22 in most environments.  Lighted urban areas, we have used up to 12-15x with good success.

As for the "all of a sudden" non-restriction, this was and is all about supply and demand and internal company policies.  Mil units come first and this usually always dictates the said company has enough units to go around after filling their Mil contracts first. Presently in the Raptors case, these units are not in large scale current contract any longer.  Hope this helps.

Vic

The 27 performs better for longer ranges because of its large objective and faster lens vs. it's little brother. It brings in so much more light, which allows for much more magnification in extremely dark conditions.

Where the sweet spot is 8x for the PVS-22, 12x is the sweet spot for the 27 in the same lighting conditions. Hope this helps.

Vic