I started using the Resmed Escape II about 2 weeks ago. It's a real small unit that runs on 12 volts DC or 110 volts AC. I use the humidifier which doubles the size, but with both in the travel bag with hose and mask it's about the same size as a laptop in the travel bag.
Mine has been working great and seems to be getting better as I learn more about it. Without the humidifier my mouth gets real dry which wakes me up. If you want to use the humidifier and camp you will need a battery and a TRUE sine wave inverter. If you are ok without the humidifier then you will be good to go with 12 volts only. The humidifier requires the 110VAC. Took a bit of research for me to get that sorted out. I'm big into camping and need the 12 volt capabilities not to mention living in Louisiana and power outages.
The clinician (spelling) at the sleep clinic I go to rides a Goldwing trike and also uses CPAP. He knew exactly what I needed and fixed me up.
I was having trouble with the mask leaking and discovered that I wasn't putting the seals back in the mask properly after daily cleaning. Fixed that and all is well.
It's basically a mechanical system. Look at it in a positive mechanical way and you'll figure it out. I also spent the first week playing with the humidfier. Changing settings and sleeping with and without the humidifier taught me a lot.
The only problem I have is going to bed early. I work a 7&7 schedule and work nights. Takes me a week to swap over and then it's time to start nights again.
Go to
www.cpap.com and click on the forum. You'll learn a lot.
Hopefully your insurance will cover the machine you decide on.