It wasn't the worst night of sleep of my life, but it definitely wasn't the best. The beds were cheap and simple, all the wires and electrodes were annoying, and the rain on the metal prefab clinic building was loud.
To be honest, I went because my partner complained about my snoring. If it meant a $3-4k bill, I would not have gone.
Sleep apnea is the most common sleep disorder, and it's easy to identify with equipment that you take home and use for a night. If you have it, there are different treatment options depending on the cause.
Other disorders are more difficult to treat, and sometimes they just don't have an answer. I'm still struggling with my sleep issues - they can describe it based on a full sleep study, but there's not a good categorization for it in the DSM, which means they can't even say if it's physiological, psychological, or a combination of the two. That makes it very hard to treat.
I really have the least amount of respect for sleep clinics I have had the displeasure of working with.