Simon, IMO the reason for the bad results was clearly your lack of knowledge on the subject. that's not a criticism, you just clearly need to learn what works well on the LM rotary system. As Jason said, it's night and day to HWE. Your first mistake was using Pure Clean. It's about as far away from most LM cleaners Top 5 chem list as you can get.
Try using; Fusion Clean (Solutions), awesome results, especially when pre-sprayed with M-Power.
If you don't like the Solutions camp, then Craftex Catalyst is pretty good.
Roto Brite 2 is pretty good but IMO not as effective as Fusion Clean.
Lastly, ACTIVATOR is still a brilliant product but unless your a registered DF operative, you may have trouble getting some. (although I've heard DF are relaxing their process).
Did you have an appropriate wringer on your bucket? Very important for rotary cleaning. (Notice I avoid the term bonnet as it's a stupid name). The pad must never be dry!! (Unless youre fixing an overwet carpet situation - that's the only exception). But just as the pad must never be dry, it must also not be sopping wet, otherwise the point where you place it on the carpet and lower the rotary onto it, WILL get a wick stain. Hence a good commercial grade wringer is VITAL, forget about trying to wring it out with your hands.
Next - very important; when you first lower the machine onto the pad, immediately spread it across a wide area. Don't work a small area at a time. Spread all of the solution on the wringed pad across 20sq/m. THEN, return back over the area and evenly clean.
Turn your pad over and continue. It'll help dry the area and help lift the soil.
just some starters because your photo looked like you had made a number of these mistakes. I could 100% get your 'HWE'results in that pic, from rotary. With Dry Fusion I could probably get better, with standard rotary and Fusion Clean, I could match it.
Cheers, Deano,