Here is what I think:
On Real Dirty carpet, you will get that visual Clean/Dirty streaked look with any multi-jet wand.
Bottom line, it's nearly impossible to get a 14" sheet of water to go down evenly.
You won't notice this on light soil.
Add to that on THICK piles, the jets physically sit closer to the fiber, you Will get some pile distortion,a nd you will get some Jet Impact either right at the center of the jet where the pressure is greatest, or at the "overlap" where two jet streams cross.
This is made WORSE as the
Glide wears, placing the jets closer to the carpet.
So...add the wear, and a really thick pile and you will see the above on real dirty carpet.
I will say I have helped all the above, on THESE specifc carpets by turning your operating pressure Down, and making a slower wand pass, allowing the water longer to rinse the soils with each pass, ADD to that making a jet change to a larger size (higher flow) and you will overcome 90% of the problem, as you are now Super Rinsing at non-streaking pressure.