Hikari is the ONLY brand of worms and brine shrimp I ever buy at my local pet store, and the reason, is quality. They use no fillers, unlike the San Francisco Bay brand, and the worms/shrimp are always consistant in size and mass.
However, the freeze dried type has a couple of cons; first, they do not sink the way frozen (thawed) or fresh worms do. Reason, of course, is the fact that these a VERY dry and will need some moisture to start to sink. This means that if you want your bottom feeders to have a chance to taste these, you'll have to use tongues to bring the dry worms directly in front of them or to their inmediate area, or the rest of mid to high swimmers will devour the worms before they reach mid levels.
Second, again, their dryness makes them a bit harder to eat, at least right away; I noticed one of my fish had one stuck in its mouth, not being able to swallow the dry, stiff worm. So, to fix this problem or to at least make it easier on your fish, you can pre-soak the worms in aquarium water (never soak them with foreign sources)for a few minutes, then dump the lot into the aquarium, the now wet worms will sink easily and will be that much easy for your fish to consume.
I'll be honest, I always try to feed as close to fresh as I can (13 yrs now), the Freeze Dried Hikari worms are good for a quick, "I'm out of fish food" solution, but I wouldn't recommend it for a daily feeding routine, unless you are willing to do what I said above. Also, as another reviewer said, you get A LOT of dust and tiny clear chunks, which are worm peelings or skin if you will, which have no benefit on your fish diet. My two cents.