I've killed many deer with various shotguns, although I've never used an 11-87. With the quality rifled barrels and saboted slugs available these days, 1-2" groups @ 100 yards are achievable with most shotguns. Not to dissuade you from purchasing the Remington (it's on my wishlist too), but don't think that Mike Hanback's accuracy cant be duplicated with other slug guns.
Check your local laws before you load up any slug gun with 5 shells though. Shotguns here MUST be plugged, and if I'm not mistaken, it's a pretty common requirement.