Originally Posted by TomJD

One advantage of this style FD is that when pedalling uphill with increasing tension on the chain and needing to downshift that you don't need to rely on a spring to make this critical shift, but instead can directly pull the chain over with the cable (like the RD). In contrast when upshifting there will tend to be less tension on the chain and so you can rely on a spring to make this shift.

Originally Posted by steelbikeguy

I concur.

There is a hill on my commute home from work that has a sudden transition from a few percent grade to 14% grade. There have been a number times where I waited too long to drop to the granny and tried to let the Cyclone derailleur spring shove the chain off of the middle gear and down to the granny gear.
Well, as long as there was tension on the chain, that little spring couldn't do the job. It is possible that the Spirt or Compe V might have been able to do the job, utilizing my strength to force the lever.