depends on your shotgun really. over the course of two or three years, i set my slug gun up for one thing; accuracy. i hated lobbing rifled slugs into a "pattern" at 100 yards. ended up with a fully rifled barrel, shooting sabot slugs, and a bushnell banner 1.75-4x32 scope (the same one you are looking at actually). this combination will shot a 1-1.75" five-shot group at 100 yards. while hunting, accuracy is #1 for me, so i choose the scope.
i have hunted with red dots in the past and found that i just didnt like them. they are fast and more than accurate enough for 50-75 yard shots. the main problems i had with them was that i didnt like depending on batteries and always having to carry a spare battery or two. also the dot tends to wash out when hunting in the snow on a bright day. in the end i would prefer decent iron sights instead of a red dot. ghost ring sights or standard rifle sights are still very fast to get on target and more than accurate enough.