Like poster #2 posted Underwood ammo is super hot. I've shot most of the +P 38spl ammo out there in my LCR and underwood ammo was the hottest. Also it doesn't seem to have more of a kick then your regular +p stuff. Yes it is more expensive but it not like going to the rande shooting boxes of it.
What do you mean by "Hot"?? Higher velocity? If it has a higher velocity it then has higher recoil. You may not notice a significant change, but it still does have more recoil, simple physics. You can use any formula that you like to calculate free recoil all will show you that the recoil is greater. If you shoot a 125 grain out of your gun @ 800 fps, then you shoot a 125gr @ 950 fps the recoil is greater. Be Safe,