Read Dr. Ashby's arrow lethality study here and make up your own mind.

If I was after bear or anything else bigger than a deer, I'd use the 2317. OR a carbon arrow that has been weighted to equal the heft of the 2317. In fact, I'd put my money on the weighted carbon to penetrate slightly better than the aluminum due to the smaller shaft diameter and less friction. Or, I'd use one of the carbon/glass composite arrows, my favorite of which is the CX Terminator Select. Good weight without having to add extra weights, and a small diameter.

When it comes to shooting a living creature with an arrow, I do not want to gamble that I can get enough penetration to make for a quick kill. I KNOW heftier arrows will do the job. Flat trajectory is nice on the 3D range, but I shoot lots of shots on the 3D range I'd never consider ethical in a real hunting situation. If the critter is far enough that I have to worry about trajectory, it's too far away to shoot with a bow, plain and simple.