One of the main purposes of a feeder Stuart as opposed to loose feeding is to ensure the feed gets to the river bed without first being taken downstream by the flow, when using an open ended cage feeder you can compress the feed, and /or maybe alter the consistency of the feed to suit the release from the feeder you want to achieve dependant on how fast or slow the flow is.
Likewise using loose feed, you can stiffen or loosen your feed and make balls which will hold together - or break up as you wish again depending on what you want to achieve considering the flow of water.
If you want the ball of feed to hit the bottom as quickly as possible a good way to achieve that is to mould the feed around a heavy stone, alternatively the other extreme is to either make your balls

very loose or litteraly feed your swim with loose feed not bound up at all which will leave a long trail on the river bed, if you want this type of feed all in one place on the river bed then a bait dropper is the best way to go.
Once this loose feed is on the bottom, it's suprising how in all but the fastst of flows it will get lodged in the nooks and crannies of the gravel, and river bed detrius.
So i would say in answer to your question both methods can be adapted to suit whatever the flow, it just depends on what you are trying to achieve with your bed of bait.
Regards
Ian.