The 357 sig was developed specifically to mimic the 125 grain 357 magnum load in an autoloader platform. It does this well.
It's drawback? That's ALL it does. Period. Given the physical size of the round, that's it. Not really a fault, as that is its intended purpose.
10mm? It is much more flexible. Anything from 135-200 grain slug weights, and muzzle energies that go from 40 S&W clear up to exceeding all but the hottest 357 mag ammo, and can rival some 41 mag loads.
If I were forced to chose between the 2? It'd be 10mm by a mile. Simply because of its flexible nature. Everything from urban self defense, on up to good "woods gun" caliber.