I am using ZM62 for last 2 years, and during last 6 month I went from 25 to 28. As my stock of 62 is close to 0 now, it was time to finally try 62F (orange). My set up is Tk Onigiri and ZM 62 and 62F at 27/28. First impression was not really good, as I was missing power. But after 1,5hrs of MS, I was quite impressed. What I can comment now is that 62F has a much softer feeling at it is generally more user friendly string. I can understand that some lovers of 62 will not like 62F and this is imo connected with player´s level. As my level is not so high I was happy with 62F at the end especially because:
Clears: much easier and 0,5-1,0 m longer with 62F
and
Backhands: the same as for clears!!!!
Smash: weaker with 62F, not by much
Blocks and net play: better with 62, but this aspect can change as you get to use to new string
62F moves a lot even at 28 imo. It moves as much as 62 at 25! So this is what I can comment. I do play more XD or MD, where clears and backhands are not so important and what you want, is to have o good smash, but so far not bad.