As a solo diver, I believe that it is as much, if not more of a mindset than a skillset, and I have yet to find a class in any industry that teaches mindset. I know divers who are more experienced and talented than I, but would not fair well alone, they are people/buddy oriented and that translates to their diving as well.
The skills and concepts you need to dive alone are all the same ones needed to dive with any degree of competency at all, solid buoyancy, situational awareness, navigation, gas management and the ability to think and act under pressure. Most of these things will(should) be taught and reiterated in every class you take, some, like how you handle stress are probably more nature than nurture.
A great instructor will give you much more than the course outline says, and thus would be worth the money.
However in this case I truly think if you are ready and capable of becoming a long lived solo diver, you should not need this class, as you should have already been thinking about these concepts, skills and ideas before you finished OW.
Having said that, there are three key components to any class, scuba or otherwise. (IMO)
The course standards. I.E. what will they make you prove, and at what level, when you finish the course. There are a lot of fluff classes out there, avoid these, they are a waste of money.
The instructor's knowledge, commitment to education and integrity. Instructor needs to be extremely well versed in the material, both book and practical, should be teaching because they love to convey knowledge, and should have no problem failing your punk @$$ if you don't learn the material, regardless of their personal consequences, i.e you won't take another class with them.
Last, your commitment to the learning process. The whole you can lead a horse to water thing.
I am sorry, I have not taken this class and perhaps since you asked for those who have, I should stay out of this. However IMO this class is worthless to those who are going to be solo divers. I would however pay good money to a good instructor to mentor me through the process of learning to dive, without having to structure things in this class environment.
Of course, this class in invaluable if you need the card to dive alone in certain places. If you plan on that then take the class regardless of what you think you will get out of it.