Having an aritficial gravity gradient strong enough to pull your ship/station/blah into atoms thrust onto you would you make you piss with yourself with fear (for a very short amount of time) no matter how strong it is, I don't think there's any argument there.
I think it would be more destructive to have the matter pulled from your target remain in the real world, spewing out lots of energy at it as it eats it. With the sort of reactions you're looking at in those cases, you'd be blasting everything in the area with a pretty full-on energy blast.
I think I'd dig very much going "blip" on an enemy frigate and turning it into enough superheated matter and energy to ahnilate the shields and melt the superstructure of anything inside x kilometres. I can see that being a very effective anti-blobbing weapon. Frigate spam? Not any more!
You get that with a black hole as well, but you have to wait for it to completely evaporate to get the final, apocalyptic release, and exact time when that happens is related to how much it ate.
... mind you, according to wiki a 1-second black hole has a mass of 2.28 × 105 kg, so in sins terms it would probably release all it ate as radiation as soon as you turn it off or near enough as to make no difference.
... isn't fanta-physics fun? 
... also, pre-petitioning to have the black hole weapon do an AoE anti-shield damage effect centered on target when it swiches off 