I have rode with a hackamore a couple times but not much. I think it's ok but I wouldn't use it on a daliy bases
A hackamore presses on the sensitive nerves in a horse's face, id never personally use one, even a Pelham tomb thumb is better than a hackamore unless you're a really really gentle rider. It doesn't just risk hurting your horse but actually injuring it if you don't know how to correctly use it.
Rose is right. A hackamore can be very useful for some horses IF you know how to use it correctly as it can easily injure the horse. With soft hands, there is no problem.
I ride in one because my rescue horse gets anxious and inconsolable when you try to ride with a bit. I've always liked them. If used incorrectly (like any piece of horse equipment) it can be harsh and cruel. However, with soft hands it can be an asset. I like to move off of mostly leg and verbal cues so it works really well for me.
Sometimes I do but it is quite occasional. A hackamore has advantages and disadvantages. It is incorrect to assume a hackamore is milder than a bitted bridle! The main advantage is you ride bitless and with looser reins. It is a great alternative for sensitive horses or that have mouth pains. But is it also a very severe and hard tool. A hackamore put excessive pressure on the nose's cartilage and on the neck so careful with your hands!