Read everything written by Elmer Keith. You are not going to learn the answers to your questions on an internet forum. (you might but you're going to have to sort through an awful lot of nonsense.)
I've found that LSWC bullets perform better on deer than heavy JHP.
I believe it boils down to the bullet companies make a lot of money on JHP through marketing. Seen 'em fail too often in the real world.
.44 Special: For those who get it, no explanation is necessary. For those who don't, no explanation is possible.