I've had excellent experience with them, albeit a learning curve. Aside from a pile of corn, I've not seen anything else attract so much attention from literally every critter in the forest. First time I put one in and hung a camera it was like watching the discovery channel. Vultures, coyotes, deer, raccoons, squirrels, frogs, foxes, bobcats, everything.
I'm a bit partial to water tanks so I apologize if this becomes a long winded post. In my experience it's all about location. My first was a failure. I put it next to a plot and although it was a busy spot, it got the same activity as the plot, at the same time. Much of the deer activity was nighttime.
My second attempt was 150yds down a ridge from a plot. I hoped it would be a hotspot for cruising bucks. Turned out lackluster. Activity was almost exclusively bucks but was too random to predict for hunting. It was nowhere near doe bedding and does rarely if ever went out of their way to visit it. Lessons learned.
Third time was a charm. I placed it along a travel corridor that stretched from buck bedding, past doe bedding before reaching a destination plot. The line starts at a scrape just below buck bedding, 200yds to a mineral site, 50yds more to a scrape beside the water tank, then 150yds to the plot. There's always one or two scrapes open up in that last 150yds as well. Doe bedding is in a briar thicket on a flat just above overlooking the water tank. Heading to and from the plot, the does congregate at the water for several minutes as fawns play and every deer takes a drink. Naturally, bucks stop for a visit as they cruise past doe bedding and plot, and it happens any time of day or night all season long, nearly daily. 3yrs straight I have killed or seen a big mature buck going to or from that water tank.
I'm planning for at least two more tanks this off season. They have become a staple habitat feature for me. That said, the properties they're on don't have local water sources. It's hill country with seasonal creeks in the bottoms. The closest water to the nearest tank is a pond half mile away. I've never seen a deer at the pond.
In short, yes they're an awesome feature that will get used by deer. How often and how predictable will depend on where you put it. If it's in a plot then it'll get used when the plot gets used. If it's convenient to doe bedding so they can hit it at their leisure, or on their way to and from, then my bet is you'll have a gold mine.