QA1 Tubular K Member - Who runs one on a street car? Reviews?

I only see QA1 PN52313 listed for 67-72 A-bodies. The installation guide on the QA1 website specifically mentions torsion bars in the instructions.
I don't have any specific comments on this K besides it is looks nice...lol. I purchased one and never installed since I ended up switching to an HDK coil over K setup. I don't see any real performance gains besides extra space to work on the engine and it may be marginally lighter. I think it is a good option if you don't have a V8 K and need one. I also think their tubular LCAs will allow you to lower the car more.