I've got some suggestions for more questions to ask.
Did the problem start suddenly? That is, were the brakes fine up until recently? Is so, what happened? Maybe the pads are glazed. Pads make a big difference in dust, noise and pedal feel, try a different pad.
Does pumping the pedal make a difference? If so, try bleeding again and be sure to bleed both valves at each wheel starting with the right rear.
Is there a vacuum leak? Maybe you're not getting any help from the vacuum booster.
CM