I've been a longtime Diva user. I got my first small Diva when I was 22 and it sustained me until last year (26 y/o), when it started to leak :( I thought it might be because my body was changing, but I didn't bite the bullet and get a new one till I lost it earlier this year. When I did finally lose my first Diva, I decided to get two cups to replace it (just in case). I ended up buying the large Diva (which stopped the leaking problem but feels a little bulky and long - a problem I had with the smaller Diva too) and the Femme Cup, partially because I could order it easily online and the dimensions seemed like they might be right for me (the brim flares out to almost as wide as the large Diva, but the cup is squatter and smaller, so I don't feel crowded like I often do with the Diva.)
The Femme Cup is my new favorite! The plastic is easier to bend than the Diva, but it is also somehow "stiffer," so it pops open with the greatest of ease. The wide brim stops leaks, while the basin itself holds a good amount without poking out of me or feeling crowded. For a an average to light period, I would recommend this in a heartbeat.
HOWEVER I've had some adventures with my period because of birth control changes for the past six months. The long and short is I've started having a very heavy flow on one day of my period. The Femme Cup does not hold as much as the Large Diva, and its holes are much larger. Suffice it to say, don't wear the Femme Cup on a very heavy day, go to yoga, invert yourself for ten minutes, and not expect a bloodbath.
But lesson learned. On the very heavy day, either no yoga or the Diva's the way to go. On all other days, Femme Cup all the way. One more reason to support different companies and have a backup.