I'm under the impression that CPAP can be a little annoying to use.
Yes there is a break in period that takes time to get your body acclimated to a mask on your face and pressure on your lungs and a hose that gets in the way , It would be similar when you were fitted for your oral appliance and it sounds like you did get use to that . Some People make friends with there CPAP on the first night and some its a on going battle every night . I remember the first night , actually I don't . I put the mask on turned the light out next thing it was morning and feeling like I was twenty years younger and full of energy . Remember going to work that day and someone asking me what was I on because as long as they had known me they had never seen me wound for sound . Told Them CPAP ! So is it Annoying ? for some , Some its a way of life if we want to live a normal Life . As eviltim put it [ It's still the best therapy we have ]