I agree on being patient with a sinking fly but sometimes fish will fallow the fly down all the way to the bottom and swim off without even taken a second look.They know its sinking to the bottom even with short or long hops its still sinking to the bottom.Its the reason for the split shot with a floating fly,its sinks but will also rise back up with short or long hops.In other words its sinking just like a wt.'ed fly but the rise of the floating fly will get reaction hits on inactive fish.
I think the reason the bream killer slowed down on catching was b/c it wasn't rising fast enough.The foam on the other flies gave it a faster rise that tiggered the inactive fish into hitting the bait before it got away.You can do the same thing with a popping bug,both the floating fly and popping bug with split shot can be a life saver in the dog days of summer.