I stir micro worms into the multI tank and the 75 just about daily. The neons in the 75 are the brightest I've seen anywhere and I think the live food is why. They also keep the multis in good breeding form. Of course they get other stuff too.
mine usually get some daphnia on a friday as that's when my son goes to playgroup which is just round the corner from a pet shop! very handy!! too handy really as I usually buy fish as well!! however, last week the delivery hadn't arrived so they had no live food at all to buy . I get it as its fun to watch them chase it!! also i've heard its good for them! natures way I guess!!
One of my 75 fw tanks has nothing but livebearers. I have a lot of floating plants in the top and regularly catch the babies to feed to the other tanks. Other than that, I'm a little funny about feeding store-bought live foods to my stock. Depending on what you get, you can introduct a lot of problems into your system. Live brine actually has very little nutritional value, although the fish love it - like candy to a baby. Black worms can contain leeches that can get down in your system. Some live foods can carry diseases. If you use live, always make sure you rinse it first. Frozen will kill any of the bad stuff you can introduce with live. I feed a variety of frozen foods as well as Spectra foods. I've been keeping tanks for over 30 years and its always worked for me. I currently have 7 totalling 400 gallons. They include a salt water reef, salt water aggressive, two 75 gallon fw and several breeding tanks.