Sleep apnea is very serious. First discovered my dh had it shortly after we were married. He would stop breathing in his sleep for a looooooong time, like 10 seconds (i was counting "1 hippopotamus, 2 hippopotamus, etc). It was very alarming. When he did his sleep study they found that he had a serious episode every 60 seconds - stopped breathing, throat closing down. Before the cpap he was always tired, looking like he had been beat up in the morning, grumpy. Since he started using the cpap, almost 10 years ago, he gets by on less sleep as it's more refreshing as he's not fighting for his life all night. His mood is better and he has a lot more energy.
i did a sleep study as my dh said i was snoring. My breathing was not stopping. i hated the study, couldn't sleep in a strange place all wired up to a machine. i think in my case they tried to push the machine on me. i don't think the study was accurate (and the second one was even worse - i spent most of the night with the mask pulled off my face). But with my dh, i think it saved his life.