I personally like the lunette better. I think the ladycup is too slippery.

it also has a low capacity for its dimensions.

you do need to find your cervix. http://www.wikihow.com/Choose-a-Menstrual-Cup read here.
your cervix is where the blood comes from, so it's important. it should sit around or below your cervix. if your cervix is unreachable, you need a long cup or you'll have to bear down a lot to remove it.
some get what's available locally or comes in their favourite colour and are lucky... others are not. all cups are *good*, it's just about what fits you best.
TPE is just as safe as silicone. the small meluna is really small though, i personally don't know anyone who uses it as their regular cup.
also, i'm 20 and a virgin and i use wide cups just fine. i recommend this if you have a heavy flow.
if you're not comfortable inserting things into your vag, work on that while you're waiting for your cup to arrive. stretch yourself with your fingers and get more familiar with your anatomy.

i'm not sure it's really plenty... on the other hand, there ARE plenty of posts from people who got cups that are too long or too short because they didn't bother/didn't know.
you don't have to be able to REACH your cervix, that's true. if your cup gets unreachable and you need to bear down to remove it, then you can be sure your cervix is high (on the days when this happens).

and you can't assume anything about whether the OP will need to trim the stem without knowing anything about their anatomy. any stem will be uncomfortable if it sticks out.

You've obviously been to the size charts already :o) and it's not imperative that you know where your cervix is, but it is very helpful. It's a coin-sized nub that feels "different" than everything else in there. It is probably firmer, and probably more sensitive in that you'll think "ooh, what's that" when you touch it.

Despite what the instructions say for a cup to ride low, your cup can't read so it will usually position itself with its rim (O) around your cervix. If it's a short cup and your cervix is way the heck up there (long vagina) then you might have a hard time digging it out when time comes to remove it. Conversely, if you get a long cup and put it into a short vagina (low cervix) it will probably shift off the cervix and your period will literally flow down the outside of the cup, not into it. That's because (analogy) your cervix is not at the top of your vagina, just like your face isn't at the top of your head.

Many young/virgin users automatically aim for the smallest cups but don't be afraid of length if you need it.

The Lunette is probably a more friendly cup to start out with. The Lady Cup has a much lower capacity than a small Lunette. Also, I still don't know where my cervix is. That said, a Lunette, because it's a wider cup, would work just fine if you had either a high cervix or a low cervix. The outside of the cup is also easier to grip, instead of the more slippery Lady Cup.

However, it's all about which cup you are most attracted to and want to try. Don't shy away from the Melunas just because of the TPE. It that's what you most want to try, then try it. If you don't like it, wait a few months, learn your cup and then order a new one. :D I thought I loved my Lunette until I tried a Fleurcup. Everyone is different, go with your gut. :D

it's true that ppl with high cervixes use lunettes too (don't know anyone who uses a small ladycup despite having a high cervix btw) but the length really makes no difference when it comes to whether insertion is comfortable. 40mm-wide cups range from 40 to 56mm in length and if you go sliiightly wider (43mm) you can have any length. so even if the OP wants a narrow cup i recommend choosing by the needed length.
and the small lunette is just 1mm wider than the ladycup. in fact, it's too narrow for me and it sticks out. what makes it fit many is the long stem. but you still need to reach the base for removal so a longer cup will be a better choice if the OP's cervix is high.

I don't own a ladycup, but I do own a small IrisCup which is a copy of LadyCup. very soft and squishy.
The small lunette is a bit stiffer - but I like it... it has a good balance between soft and stiff, so it pops open alright and doesn't spill in removal, but I still can't feel it. I love the Lunette stem, and the capacity gives me an extra hour.

so yeah - I say lunette (:

Ahh! Thanks for all your advice, guys. Serpent, that chart you posted was super helpful. It seems I am leaning more toward a lunette now, but part of my gut is still nudging toward Ladycup. I don't know what that's all about, but if my menstrual cup intuition is anything like my sense of direction, I should definitely ignore it, haha.

Don't know if you've decided yet, but for what it's worth: I only have Ladycup, it was my first cup and I bought it because I wanted something smooth (ok, and also because of the colours!). I did find it really slippery to start off with but I got the hang of it really fast. The one thing that makes it not perfect IMO is that the capacity is quite low, so if you have a fairly heavy period and want to use it for hours on end I wouldn't recommend it. On the other hand if your flow's not too heavy, I really would, because when it's in I don't feel it at all - and the stem doesn't poke into me, despite the fact that I haven't cut it. (hmmm... I wonder if many people cut the stem off ladycups... they might have trouble reaching it!) ;)