I have been shooting around 70@28 for about 5 years now and have had great results.
1) Confidence...I don't doubt penetration ability
2) Arrow Flight...I don't have to compensate for drop as much as with a lighter set up
3) Bigger Broadheads make for cleaner kills and can make up for those bad shots(they happen)
4) I can hunt any game I want
5) I'll come right out and say it, I feel more manly shooting a heavy bow accurately
That being said, ive made a change in my setup this year and have dropped to 59@28 and a shorter 58" set up for treestand hunting. I hope to have more maneuverability in the tree for odd angle shots and haven't had as much time to practice lately.
That being said, if I did more of my hunting from the ground I would keep the heavier set up.