Most inexpensive units are Gen 1 or CMOS. I have never used the CMOS based NV but I can say that I find Gen 1 to be a waste of time and money.
Ah, most people who think Gen 1 is a waste of money are folks who don't understand how to use Gen 1. Generally speaking, except for full moon nights, Gen 1 needs the benefit of proper supplemental illumination. With supplemental IR, Gen 1 can be fine, depending on a variety of parameters. For example, I hunt with a Gen 1+ 3x rifle scope with a large front objective lens and supplemental IR and do very well with it. I can identify deer and hogs at 200 yards on a moonless night. That is more than sufficient for my hunting needs.
CMOS is digital technology that you can also find used in security cameras. Once again, most require a form of supplemental IR illumination to be most effective. The nice thing about such technology over regular "true" night vision is that regular "true" night vision tubes have a much more limited life of a few thousand hours (more hours for higher generation, however) and sensitivity can decline with use over time and damage brought about by exposure to bright light. That is why you don't have to put the lens cap back on your day/night security cameras during the daytime.
The Pulsar N550 Digisight is a CMOS type sight and is equivalent to Gen 2+ or better (depending on the evaluation given). So being CMOS is not necessarily a bad thing. You can have very good CMOS night vision and CMOS isn't fragile compared to regular "true" night vision when you are talking about damage from bright light. I can daylight hunt with my Digisight and not worry about damaging the electronics.
With that said and given the small objective lens on the Bushell from the OP, the Bushnell is going to be a fairly limited capability NV scope. Given actual retail is now $159-189 (versus msrp), you should not expect too much. Amazon reviews indicate it to be a fairly capable short range Gen 1-like NV device that with the IR on, you can see things like dogs out to 100 yards, but blurry. One description mentioned it being great for things like camping or caving and for short range needs, it is probably great for that.
Most of the folks reviewing the scope seemed to have wanted to get a full blown Gen III+ enhanced NV device for pocket change, probably like what they have seen being shown by news crews in war zone areas, with nice capabilities out quite some distance or maybe even high dollar thermal qualities. That isn't going to happen. It is simply a short range sub $200 low light optic and it is apparently a reasonable low light optic within its indicated capabilities.