You asked my opinion - here it is.

If I had to choose from the Bushnell or Nikon you mentioned, I'd take the Nikon hands down. Much better optics IMO, much.

You should consider the Simmons Pro-Diamond scope. We have 2 H&R Ultra Slug Hunters and they both have the Simmons scopes. I bought the 12 gauge one first and liked the scope so much that when we bought the 20 gauge there wasn't a question as to what scope to fit it with. Fantastic light gathering.

The 12 has been shot ALOT and has never been re-zero'd. The 20 has never been re-zero'd either. Never a problem with either. The Simmons have full 32mm lenses (back and front). I wouldn't consider any shotgun scope with the 32mm rear lense and 20mm front. There is no way a 32/20 scope can gather decent light like a full 32/32.

I do not like and cannot understand any use for a variable power shotgun scope. I recommend a straight 4X (Simmons #7790D) for shooting out to 150 yards. If you don't think you'll shoot more than say 75 yards I'd go with a 2X (Simmons #7789D). Neither one should be more than a hundred bucks with the 2X probobly $10-15 cheaper than the 4X.

Take a look at them.

And DON'T ever think of putting a rifle scope on any shotgun. Rifle scopes can't take the unique recoil a shotgun delivers.