I have a standard 20ga. USH. At 100 yards, it will shoot under 3 inch groups with just about any quality slugs.
I "believe", the deluxe is just a bit fancier, and the light is just that, lighter in weight.
Personally, I feel a slighter heavier gun will help with accuracy.
As far as of the bolt action guns, most I have ever shot were very accurate. But, once you take that first shot in the morning woods, if you miss, the second shot is questionable. I have found that the extra second or two might allow the deer to stop and look, and maybe allow a second shot. And knowing you only have one in the gun, will always make that first shot more precise.