I flew to Texas (from Canada) last year with my Kenmore. I bought the smallest size Tutto bag for it, because that was well within carry on sizes (the next size up claims to be carry on, but I was afraid it would be just that smidge too big if they were being testy about it). I had no trouble with the scanners - at least once I learned to take all the cables and pedal out of the bag before putting it through. It never fit overhead, but was fine under my feet in most cases. On one of the planes, it didn't fit at all and had to be gate checked (as someone mentioned, even this is dangerous as evidenced by Bonnie Hunter, but my machine made it through safe and sound).
I wouldn't check it. Even fragile stuff seems to be handled somewhat roughly. Although now that I think about it, I did check a sewing machine as fragile baggage years ago. And found it on the round-about at the other end (not in a separate, fragile, location)