Motorcycle Repair: Vance & Hines Power Chamber, vance and hines pipes, performance perspective

Question
Is the V&H "Power Chamber" connection on pipes like the SideShots and BigShot Staggered really functional or is is marketing BS?

What are your thoughts on the SideShots from a performance perspective?  

Answer
My thoughts are of the vance and hines pipes are thay are the worst junk sold for harleys. they KILL more horse power and torque like no other exhaust system on the market!. I took a set off friday that took off 21 horse power. if you want a great exhaust system and lots of torque and power across the entire power band then there is only one exhaust system to go to..... WHITE BROTHERS E-SERIES 2 INTO 1 EXHAUST SYSTEM.  JOHNNY  602-705-7474