Selecting a cpap machine for travel -- small and light

There have been a number of threads in this forum about this topic in the past, I have looked through some of them on and off. Since many of them have a lot of posts, I thought I would start a new one, because I have a specific question.

I am currently using the Respironics M-series auto (with HH), low pressure <6cm. I may travel without the humidifier. Without the humidifier this one is only about 2.2 lbs, I think. So are some of those 'travel models' much lighter than this? In those other threads the types mentioned in there, the lightest ones, appear to be the same weight or heavier --- perhaps that was before this newer lighter M-series was introduced?

So what is the advantage of buying another machine for travel? I need cflex or some such pressure relief, and even though I can adapt to run without auto -- just fixed pressure, it is nice to have auto. Most travel machines seems to have limitations in features, yet people seems to like a second machine for travel. So what is that I am missing?

I would need to travel by plane long flights, I do not know if it is at all practical to think of using the machines on the plane. But where I am going to there would be frequent and long power interruptions, so a battery pack would be needed (and lower power consumption highly desirable.) Look for any help and suggestions from the good neighbors here.

Hi

I traveled with similar machine (see below) on my annual mid winter trip to London and Paris. It was light enough so it did not bother me while carrying it in a rolling suitcase (it does take up half the bag) If you travel internationally, the m series will work on 220, all you need is a physical adapter to match the plug style.

What convinced me was last year I slept through a verrrrrry good London play that I wanted to see. This year I was wide awake for all plays ( I try to do at least one a day when I'm in London, it's not often I'm out of the boonies and in a real town)

I did not use the bipap on the plane, though I do sleep on the plane. SFAIK, the upright seat position mitigates apnea. I did see plugs in the chunnel train from Paris to London, so that might be an option ( don't know if any planes carry them , perhaps some in first calss)

--g