Can you use tampons? I don't really know that it has anything to do with being overweight or anything.

The Luna I prefer b/c it is softer (or so I've heard) than the Diva, and also comes in two sizes. . .regular and small. I'm built really small ~ even after two kids ~ so I needed something a little smaller. The Luna works beautifully. I have also found, believe it or not, that I've not had cramps since using it. Weird, but a nice perk.