If you have read mixed recommendations I will suggest that you are reading the other keepers prefrences. Either are good foods and you still should give them a variety of food.....neither bloodworms or blackworms are a total healthy diet.....would you eat puffed rice cereal for every meal, forever.....yuck!!!
If you are using freeze dried foods, always soak in water for a while first to reconstitute it.
Gobies are a bit of scavengers (omnivorous

) too so should be happy grazing on all types of food.
The worms are also fine for molly's etc, but they also like some green foods too.
Variety in diet is most important. Fish will learn to eat what ever you offer.
example: when feeding worms put in a few flakes or pellets so they can get a taste for them. I also soak the pellets first too. If you have baby fish mash a few pellets for them also.