If they aren't flocked decoys, Texas rigs are made to be carried loose with a carabiner. Its quick and easy and my favorite way for floaters. If you didn't want them bashing around then i guess a large opening bag made for Texas rigs would be the next choice. I sure wouldn't be getting a Texas rig if I were just putting them in a slottled bag though.
A big difference in your decision is your transportation. If they are going in a boat, sled, or cart, then loose definitely. If you are hiking them in a long way on your back, then you would most likely want a bag with backpack straps.