Anything out of a short barrel is slower than from a longer barrel. YMMV with different ammo, etc.
All snubbie .357s are a little picky about ammo, but usually the manual will cover that a bit. Full house .357 loads will probably kick too much, make too much flash, waste powder because it burns too slow, and the bullets you have left in the cylinder will jump crimp on their cases, and you'll end up with a jammed up cylinder.
That said, I have a Ruger LCR in .357 and I love it.
Practice with CCI Blazer 158gr and carry Remmington Golden Saber. They're both 'lighter' loads. They have similar feels when shooting them, so you don't have to worry about practicing with something that doesn't shoot like it would when you might use it for real (practicing with 38 special). The Speer Gold Dot Short Barrel stuff supposedly does really well in terms of ballistics, but I prefer the way the Golden Saber feels shooting it.