Those accumulators on the brake lines do indeed do something--they add sponginess to your brakes. Their marketing department would have you believe this sponginess is desirable. I'm quite skeptical of that.
Their claim is that brake component distortions (like warped rotors) cause pressure spikes, and kick the pads/shoes out of contact with the brake surface (rotor/drum). Their accumulator would indeed add a springy quality that could reduce pressure spikes. However, conventional wisdom dictates that braking systems are elastic enough already, and efforts should be focused in keeping the systems "firm". This is one of the reasons people replace spongy old rubber flex lines with braided stainless lines--to REDUCE sponginess.
If you have a problem with warped rotors and brake shimmy, you fix your rotors.
Woe to the man who purchases both braided stainless lines AND accumulators in an effort to upgrade his system.