I have four cups right now: a Diva size 2 (stem completely trimmed), a large Yuuki (stem slightly trimmed), a large LadyCup (stem intact), and now the SheCup (stem intact).
The SheCup is a little smaller than the Diva. It is just about the same length (including its ball stem) as my Diva size 2 with the Diva's stem cut completely off, but narrower. Capacity is also less. The holes on the SheCup are lower than the Diva, and when I fill my Diva to the holes and pour that into the SheCup, it fills the SheCup basically to the top of the cup, way over the holes. When I fill the SheCup to the holes and pour it into the Diva, it reaches the 15 ml line on the Diva, and the Diva can hold way more than that. The Diva and the large Yuuki have just about the same capacity, with the Yuuki barely (and I mean barely) edging out the Diva. The Diva holds quite a bit more than the LadyCup, while the large LadyCup and the SheCup are pretty close since the LC has that set of lower holes.
As I have said before, the Yuuki and the LC are very similar to me. As you can see from my pictures below, they both have the same "sheen" to them. The rims are identical, but the LC is smooth all the way down until it gets to the little grip bumps (which do nothing for grip, IMO). The Yuuki has a ridge near the top, but it is soft and rounded, like the Diva's, and also has a nice grip rings at the bottom. The grip rings on the Yuuki feel very similar to the grip rings on the Diva to me, but they are spaced farther apart than the ones on the Diva. I don't find them too sharp, and I dion't notice them when they are inserted. The SheCup has vertical lines for grip, and they actually seem to work pretty well, at least on the dry run I just did.
In terms of squish, I think the Yuuki and LC are identical, and both are slightly squishier than the Diva. The bottom of the Diva and the bottom of the SheCup feel very similar to me in terms of squish, but the tops are different. The SheCup has a more pronounced ridge than the Diva (it reminds me more of the MCUK in style), and I think this ridge makes the top of the SheCup a bit more stiffer, and therefore it pops open with more spring than the Diva. On my dry run, I actually felt it pop open, and I rarely feel that with the Diva, and never with the Yuuki or the LC. This ridge, however, made inserting the cup much more uncomfortable for me than I am used to. I think if you are used to cups with defined ridges like the MCUK, Femmecup, Keeper, etc., this ridge won't even be noticable to you. However, if you only use the more rounded cups like Divas or LCs, this ridge will take some getting used to. Once it was inserted, I could tell it was there more than the other cups, but I didn't wear it very long. I suspect the feeling will go away as I wear it for longer periods of time.
ETA: I am wearing the SheCup this morning (I am a continuous use person), and again it was a little more uncomfortable to insert due to the ridges, but now that it's in and settled I can't feel it at all. Keep in mind that I have also had two kids vaginally, and I am almost 40 so my experiences with how a cup feels are surely entirely different than someone who hasn't had kids and are in their 20's would be ;)
Now, on to the pictures :)
Here are a couple of comparison shots with all the cups lined up:
Left to right: Large Yuuki, Large LadyCup Lotos, DivaCup size 2, SheCup (same order for both pictures)
DivaCup size 2 and SheCup (the Diva's stem has been totally trimmed off):
Large LadyCup Lotos and SheCup:
Large Yuuki and SheCup (the Yuuki's stem has been slightly trimmed):
And here are some pics comparing the rest of the cups to each other.
Large Yuuki and large LadyCup. See what I mean by the sheen? It's the same on both cups. The rims look identical, too.
Large Yuuki and Diva size 2:
I forgot to take a picture of the LadyCup and the Diva together but I know that has been posted before.