I've been hunting bear for over 20 years, and live on a small lake just outside Vancouver, and currently have (at last count by the Wildlife Officer and me) 8 bears roaming the immediate area.
I agree with Jeff for a number of reasons, the primary one being that black bears are so much more unpredictable. If you get a black bear that has become territorial over an unnatural food source (dumps, garbage), they are damn scary.
Any black bear you see that are not in the deep wilds have an excellent chance of being much more dangerous than you'd think.
Just watch the bear behaviour at a city dump sometime, and you'll see it's WAY different than you'll find in the deep woods. They almost act rabid.
Of those 8 bears roaming the immediate area around my house, 2 of them have had to be put down within the last month due to their aggressive and dangerous behaviour. For instance, about 6 weeks ago, I had one watch me through the window of my house, and lean up against the door to get in, despite me making noise and trying to scare it off. It took all of 30 seconds for me to go and grab the shot gun with the 3" slugs, but it eventually ran off. Typically, they run like jackrabbits when you tap on the glass, or make any noise. This one felt like it was stalking me. Not. Normal. Called the wildlife officer, and he agreed, and 2 of them patrolled the area for the next 2 days until they were able to dispose of it. (I live close to a provincial park, and they were worried about the visitors having issues).
Mind you, we've got lots of problems right now with both bears and cougars in the area, due to the lingering snow pack and scarcity of natural food.
Here's the pic of the bear that freaked me out:
It broke the lawn chair, and then leaned up/on the door, watching me as I yelled and waved my arms. At that point, I was about ready to fire a slug through one of the glass panes in the door, but it eventually pissed off.
As to best hunting loads, personally, I think shot placement matters more than the actual round used.
The BEST effect I've ever seen was when I dropped one with a broadhead from a crossbow, just behind the shoulder and into the lungs... it just stopped.
Other than that, I've never been a fan of sabots, and always prefer 3 or 3.5" slugs in my rifled shotgun barrel. Also never had issues with my .30-06.
$0.02 (CDN)