Here is my opinion.
I recently did a community centre. I have also recently aquired a super charly pad system.
I presprayed with no. 9 and agitated, then HWE'd. Believe it or not there was little or no improvement. I then ran charly over it. The results were brilliant, unbelievable. I know that HWE helped, I also tried charly's first (the hwe had no VISUAL) impact.
Don't know about D/F, but Charly's... I'll rave about them all night, brilliant.
Chris