The issue, if any, would likely be at security, and TSA rules say they are permitted but if it's large i can see you being asked to open it so hope you aren't superstitious.

I've never even been questioned, but mine compresses pretty well.

On the intl flight there should be plenty of room overhead, though I'd suggest you put it into the overhead late on, lest is sits behind things that shift around as that could break it.