As I mentioned previously I have actually weighed the bars now... and I have pictures. For the record I'm not done with my install, but I did remove my ZOK rear sway bar tonight. I was able to remove the old bar by pulling only one rear toe adjustment link, and unfortunately I can not find the angle to install the new bar with only one link pulled. My main problem is the drivers side link doesn't want to break free... and I'm out of time for tonight to work on the car.
Without much further wait... the weights (see what I did there?)
Stock GXP Rear Sway Bar: 6.6 lbs.
Z0K Rear Sway Bar: 11.4 lbs.
WERKSRacing Adjustable Rear Sway Bar: 11.2 lbs.
Yes... the adjustable, by my bathroom scale on my somewhat levelish garage floor is just slightly lighter. I'd wager a guess you'll never notice the difference! And yes... I include the brackets in all cases and the locking rings for the WERKSRacing bar.
Picture:
Top: Stock Bar
Middle: Z0K Bar
Bottom: WERKSRacing Adjustable Bar

And to make it a bit more clear... here is the toe adjustment link (bar) that you not to free up. Take the nut off (you might need to hold the top from rotating, I did not), spritz with a blast of PB Blaster, let sit 30 seconds, and then BANG IT WITH A HAMMER.

