I ordered a soft MeLuna at the end of February, one with no stem, as I've always completely cut the stem off other cups (Keeper, Diva, and MoonCup). I was delighted to receive a second cup with my order.
Finally today I was "in the mood" to try my cup. First I went with the softer cup, but couldn't get it to pop open. I finally gave up and tried the stiffer one they'd sent, which has the ball stem. To my complete surprise, it is comfortable -- I do not notice the stem at all, even though it definitely rides low. The reason I decided on the MeLuna was due to its shortness. The Diva was much too long (and very uncomfortable). I had some success with the Keeper and MoonCup over the years, but eventually they too came to bother me - I think as I had more children (4 now) and also developed a rectocele (oh yay).
Anyway, I wore the MeLuna for 7 hours for the first run, and did not have one whit of a problem with it. CD 1 is usually very light, so we'll have to see how the next few days go, but I am so pleased with my first go at it. Definitely glad that they sent the second cup, because I'd have been really really disappointed with the softer one not working today. I'm usually house-bound with AF; today I was out and about, getting in and out of the car, walking around, generally being normally active, and I didn't even have to think about my period. Exactly how a cup should be!
So for anyone whose had trouble, don't give up! The right cup is out there, I'm proof ;-)
ETA: I can't get the continuous use tag to go away.