We feed in "feedings"
One; because I found that the dominant ones would eat all the food and the more timid wait till they were done -and get non ( work full time and cannot be there to constantly refill the dish). The dominate ones were getting too large. I find it is much easier to control what each cat is getting with feedings, as you can watch.
Two; This came in effect later, but we are now on three "types" of cat food ( kitten, adult, mature) Feedings are the only way I can make sure the right one gets the right food.

As long as your cat(s) aren't gaining weight excessively & are all getting the right amount , you could free feed. I personally prefer feedings.