I agree that "power down" is worthless.
I installed a Lewmar Pro-fish 700 (free fall) on my boat years ago and love it.
Thing is, when you are anchoring most of the time you are going to be in neutral, and therefore the boat is going to be drifting back with the wind/current as the anchor falls, thereby negating the "sailing anchor" effect. Besides, the anchor/chair/rode doesn't fall THAT fast "into a ball", it is slowed by the friction of it coming up through the locker, around the gypsy, and out over the pulpit/roller while falling.
In fact, I (most guys?) usually power back in reverse while the anchor is falling in order to stretch out the anchor chain to ensure the blades get a good bite when they hit the bottom.
Only issue with this (and any) windlass is you have to remember to cleat it off once the anchor bites. DO NOT allow the windlass to hold the boat at anchor without cleating it off!
Trust me on this because I learned the hard way....although I really KNEW this before, I got lazy and "just left it once" and subsequently had to have my unit rebuilt due to a broken internal frame around the gears...it's just not built to handle that stress, especially when there are wakes and/or heavy seas.