I put one on my wife's bow because they are extremely easy to set up, it removes the possibility of the arrow falling off the rest as she is getting her bow into position, and it is inexpensive. All in all it is a great hunting rest. She easily shoots 4" diameter groups at 30 yards, and for a first year shooter who averages about 40 arrows a week spring-fall, that is pretty darn good.
When I first read the "not accurate?" part of the thread title I thought I was going to have to argue that it was. I am glad that all I have to do is agree
The only reason that I do not have one is simply because I have been using a metal prong rest for probably 15 years and I am just used to it.