Hi Marie, If you're going to be traveling with either of these machines I would choose the Opal.. It was made to be a take it with you to class machine with most of the features of The higher end Viking line..The Sapphire is a larger machine. longer bed for easier handling of fabric..I'm not sure how many more stitches/memory/fonts it has.. They both have the sensor system...to me size & $$$ is the difference... I have several of the Viking machines and almost got the opal..but didn't.