"It saves a cook from having to fill up a big pot in the kitchen sink then lug it over to the stove."

What about lugging it back to the sink to drain?

I once was renting a house that had one, but I never used it. The water that came out of it was cold, and I'd rather lug the pot of hot water to the stove than wait twice as long for it to boil. But that's just me and my impatience.

I've always found these baffling. As has been mentioned, you still have to haul the boiling pot to the sink off the stove. But for me, the biggest drawback is that I really cook a lot, and the backsplash by the cooktop gets really grimy and oily. The last thing I need is a hard-to-reach faucet with tons of nooks and crannies back there that I have to clean.

I'd be concerned about the cleaning, too. And about how hot it'd get if I needed to use it while I was cooking something else on the stove.

I don't really see the point--in a busy commercial kitchen, sure, but in a home kitchen? A bit showy, I think. It's not that hard to use a smaller pot to fill a larger one that won't fit under the faucet, and even I can carry my large canning pot full of water from the sink to the stove, and I'm pretty small. And ditto on cleaning it!

Now if the stove had a drain, I could see this working well and then we could call it a "stink."

You should never cook with hot water that doesn't come from a filtered source. Hot water can introduce all sorts of yucky things into your food. Then again, I live in 100 year old house and goodness knows what is in my pipes!

That being said, I'm planning my dream kitchen and I'm really leaning toward a pot filler. I don't even boil all that often, but we're replumbing the entire house so it's not a huge expense to get the water to that source.

Robin Sue - Ha ha ha! A stink! That's great!

Actually I think I saw a sink that cooks. I wish I could remember more about it.

If I need to add water to something, after the initial fill up, I use my hot water dispenser and a measuring cup.

Our water here is pretty good so I don't worry about filtering it.

I think having a large sink with a tap that arches up high enough to clear a tall pot would be preferable to an extra feature.

I also stopped using hot water straight from the tap after reading about how the water is contaminated by lead from corroded plumbing.

I think it's divine!

Faucets eventually leak.

I have one. They're overrated, function-wise, but they look cool and if you choose an inexpensive-er fixture, the additional plumbing run is not a very big item in the overall budget, particularly if you are designing/building from scratch. I think of mine as jewelry for the kitchen, although I do use it often.
And as someone pointed out, draining the pot is just as much or more of an issue. In my next kitchen, I am definitely going to do a drain next to or behind the range to address that.

I work at a Sushi Bar and the cook in the back has an AMAZING setup for his stove/broiler/oven-he-doesn't-use-cause-he's-Asian/grill. The Stove though...so much more than a stove. It slants down to a trough at the front and feeds into a screened drain at the bottom, and the whole thing can be cleaned in seconds. The burners have faucets above them, that automatically turn on when they are positioned above the wok/work area. The burner puts out a fire that would make Torque Amada shy, and the vents draft so well, I can stir wasabe paste on the stove without smelling it.

I wish my wife would let me make a kitchen from a Restaurant Supply Store.

I think it's extremely extravagant and unnecessary. Really: how far is it from your sink to your stove? Pot too tall for your sink? Sit the pot on the counter next to the sink and use the spray attachment. Don't have a spray attachment? Fill a smaller bowl and use it to fill the big one.