Guides here in Alaska want you to take out both shoulders period. Then once the bear is down you can finish it off with a heart/lung shot. That way they don't lose any paying clients. OK, OK, that's for Brown Bears, I know you guys are not hunting them, your hunting Blackies.
For Blacks they want a shoulder or heart/lung shot. Have never talked to anyone that likes a neck shot. They are looking for the highest likelihood of a good shot that will kill the bear. A neck shot is too easy to miss the spine, and a wounded bear is not what they want to look for in the alders. A shoulder shot that breaks one shoulder will slow the bear down so a second shot can be made. Brake both shoulders and bear can not run away. Heart lung shot bear may run away, but will be found dead.
Personally I go for breaking both shoulders. With a .35 Whelen if you take out both shoulders the odds are you will take out both lungs as well. A finishing second shot is seldom needed.