They are more of a thing for busy people. But really, what's the point of being to busy to feed your own dog? I personally enjoy feeding Chester rather than a machine doing it for me. Also the dog will bond closer to the person that feeds it. I have no idea if a machine effects that, but I don't want to risk that.
If you have to leave for work early in mornings then maybe the automatic feeder may be an idea. What are the reasons you're interested in one?
The biggest con is that they can malfunction. I have an auto feeder for my cat. It has two compartments with a timer on each. Timer goes off, and the door with the food opens. On one occasion I was going out of town for a couple of days, so put food in for that night and the next morning. Cat tried to get into the feeder, and ended up flipping it upside down. She's not a very smart creature, lol. Anyway, timer went off and the doors couldn't open. Good thing I had someone coming that night to check on her and refill the feeder. For that reason I won't rely on it- I mainly use it so that someone can only come once per day to feed her rather than multiple times.
I also know someone that had one with a jug of food on top, and you set it to deposit a certain amount of food at a designated interval. His cat learned to stick its paw in the feeder and flip the lever to let the food out.
Those were cats that caused problems with theirs, but I would imagine that a dog could also chew on it in order to get the food out. Personally, I wouldn't trust it with a dog.
Automatic pet food containers have many benefits that make it easier and more convenient to feed your pet, including…
Storing extra food in the additional reservoir or container, keeping it safe from pests as well as an uncontrolled appetite
Allowing for predictable mealtimes even if you cannot be home to feed your pet – ideal for long work days or traveling
Providing smaller, proportioned meals more frequently, essential for helping pets lose weight or managing health conditions such as diabetes
Hefty size and structure helps keep food containers from tipping over so food is not wasted, even with enthusiastic eaters
Feeding outdoor pets safely and regularly without leaving excess food available for wildlife or pests to access
Cons of Automatic Food Dispensers
Despite their benefits, however, there can be problems with automatic food dispensers. Pet owners should carefully consider these potential problems…
Generally lacking sensors and will continue dispensing preprogrammed meals even if there is leftover, uneaten food
No way to monitor which pet is eating which meal if multiple pets are sharing the feeding area and may usurp one another's meals
Dispensing action can be noisy and may be disruptive to sensitive pets, keeping them from feeding even when hungry
Generally works best only with dry food and kibbles of certain sizes, so they may not be versatile enough for every pet's diet
Cleaning can be difficult in more complicated designs and the unit may need disassembly to thoroughly clean moving parts
Feeder will not function if the batteries wear down or power is lost, which can mean missed meals and disrupted feeding