Today I received my LC in the mail, and although I'm not on my period (will post again once I've used it then), I had a few observations for comparison:
Insertion - holy CRAP this is easier with the Lady Cup, even though it's larger in diameter. It seems actually designed to go comfortably into my vagina. The LC becomes warm and bendy to the touch and slides in smoothly, whereas the Diva always felt like a hard, sticky, ridged dome of plastic regardless of temperature.
Popping open - some on here have found that it's harder to get the LC to pop than the Diva, but I found the opposite- and I tried several different folds, all of which worked immediately! Because (a) the air hole are distributed in a kind of zig zag and (b) the rim is stiff, moving the cup around just a little bit with my finger caused it to pop open within moments. I always had a hell of a time getting the Diva to pop, resorting to bizarre insertion positions combined with squatting, Kegels, drowning my sorrows in ice cream, etc. Even then, sometimes I just couldn't do it.
Suction - once I insert it, the LC has a death grip on wherever I put it in my vagina. This may be due to the larger diameter, but it seems to be more than that. I think I get way better suction with it than with the Diva, period. Sometimes just tapping on the Diva would make it lose its seal. I think this has to do with the fact that the cup is softer and shorter, which allows it to more easily maneuver into a position in my vagina in which it can open and suction. Because the Diva was so stiff, I couldn't get it into a good position.
Comfort - although the LC is softer than the Diva, I can definitely feel the difference in diameter, and so far, I'm not a fan. It feels uncomfortable, not just "present." Then again, I always felt the Diva too, which was super uncomfortable at times because it always made me feel like I have to pee. So the jury's still out on this one.
Removal - yep, the LC lives up to its reputation as being very difficult to remove because it is softer and therefore the seal is much harder to break. But on the plus side, it is worlds more comfortable to remove, again due to the soft material.
Based on my experiences so far, the LC might be a superior choice for women with tilted cervices and/or who experience consistent, unexplained leaking with a stiff cup like the Diva. Jury's still out until I have a leak-free day on my period, though!
The other observation: does anyone else get g-spot stimulation from wearing a cup? I walked around while wearing the LC for a while, and I nearly had an orgasm. Maybe it's because the cup sits lower in me than the Diva, but hahaha, I have to say, I wasn't ready for that surprise!