So, I totally tried one out! (after extensive research online, chose the MeLuna, medium size although in retrospect a small
may have been better for me)
Without getting too graphic,
-super easy to put in, after I got past the intimidation factor (it does look very large) and actually more comfortable to put in, in some ways, than tampons
-only slightly harder to take out than tampons
-not painful and no more uncomfortable than tampons, no change in cramping
-a bit messier than tampons but much less than pads

sick

. I didn't spray blood everywhere, lol.
-annoying tendency for it to come down too low, not sure why
-feel it about the same as tampons, or a bit more if it comes down too low
-NO leaks, although many times it felt like it was
-not smelly at all like (I find) tampons and moreso pads
-12h is totally fine for changing it, I'm not even sure why you have to change it that often (?) but I did anyway
-cost was about 28$ after shipping and currency conversion from the UK (!!!) because I couldn't find any more local brands that I liked. This is a lot more expensive than tampons for me since I don't use many at all (maybe an average of 4/month since I don't usually use them at home or at ngiht). So at about 8$/box of 40ish, umm it'd take a long time for me to make back the money. 28$=>120= more than 30 months or so, so about 3 years. I guess that's alright. Most people would use a lot more than that, though, and so save a lot more money. I could have bought a cheaper one but I thought this particular one would be best for me, hopefully avoiding buying another one.
so overall a big success! I guess I'm one of the luckier ones.
(side note: I bought a reusable cloth pad from the same vendor since why not, and that was an epic fail, although maybe if I actually liked pads it'd be ok...but yeah. epic fail.)