RE: Slug guns vs. Rifle for deer
If I could use a rifle I would. Makes no difference what I'm hunting, thick or open country. A rifle like a 308, or any deer rifle really, hits harder than a slug. You may want to consider setting the rifle up for the area you hunt, kind of like the low power scope setup you have on the slug gun, or even a peep sight.
You can usually find a hole to sneak a bullet through, and I think I'd rather try to make a 75 - 100 yd shot with a rifle. That's my opinion.