I have travelled with

1. CPAP in its dedicated bag
2. CPAP packed in the carry on
3. CPAP packed in its bag which is then placed in the carry on.

Since TSA is once again asking me to remove my CPAP from the bag, I have resorted to using 1. Not taking the humidifier works for me only when I do not use A/C in my room. Some times, I use the extra space in the CPAP bag for my netbook charger, and the mouse and an extra underwear. I can even pack my net book in it. It does make the CPAP bag quite heavy, but it could have saved me a ,lot of trouble when I had to check-in my carry on and it arrived with a 4-5 inch hole in it with a number of items missing.