I have a feeling the posts telling you a round with 158gr JHP bullet is more controllable than a round using a 180gr LSWC bullet in a 4" GP100 have never shot a 180gr round in a heavy 4" .357 Magnum. I have shot everything from a 110gr bullet to a 200gr bullet from a .357 Magnum and I can tell you there is very little, if any difference in recoil between a 158gr JHP and 180gr hard cast round. The major difference comes from how hot the rounds are. I could easily load a 180gr bullet in a .357 Magnum case and make it feel like a .38 Special.
Since we are all talking about fairly hot ammo like that made by DoubleTap, Buffalo Bore and Grizzly it's all going to have a good amount of recoil, that's why we practice. If you're scared to shoot the round you should be using to protect yourself, don't carry the gun.
heavyshooter,
I'm glad you found my suggestions interesting. I hope I was helpful.
BTW, I recommended Grizzly ammo because I've used it and it's accurate. Other Hard Cast .357 Magnum rounds like those made by DoubleTap, Buffalo Bore, CarBon and others will probably do just as well. I would stay away from Hard Cast .357 Magnum rounds made by Remington, Speer and Federal because they are underpowered.