I used to use Unique like it was a crack habit.
Especially with traditionally lubed cast lead where the stuff often reduced or eliminated leading problems. Since the advent of coatings, I no longer have to care about that particular attribute.
As a result, I can explore powders fearlessly.
Power Pistol seems to be a slightly more energetic propellant of similar rate.
BE 86 also has great potential in this role.
CFE Pistol makes fantastic numbers in many cartridges, though at first I looked upon it with disdain for the CFE gimmick.
AA #7 has seen good service. Though this may be a bit slow to call it a unique substitute.
AA #5 is closer, though I've never used it.
I have loaded 357 with both AA#7 and #5. my Marlin '94 loves #7, my 6" 686 does OK. my 2.75" 66 does not. unburned powder is the issue on that one. #5 is a good decent powder.
I have a couple lbs of CFE Pistol that I load 45acp with. Never really though about loading some 357 with it. I'll have to give that a go.