I just got the Paragard IUD right after valentines day (8 weeks after having my second baby). Insertion was a breeze (kinda felt like getting 3 pap smears in a row, no biggy, only like 5 mins long) and after that I didn't have any cramping and only spotted for about a week. I chose the Paraguard (copper) IUD over the Mirena because it doesn't contain any hormones, and so there is lots less side-effects. You don't have to worry about the hormones making you gain weight, get, acne, causing moodiness, or giving you ovarian cysts. But, you also don't get the thinned uterine lining that makes a lot of women who get the Mirena's periods go away. You will still have a regular period, with potentially heavier bleeding or more crampiness for the first 6 mos or so. I chose the regular periods over the hormones.
I haven't noticed anything different yet since getting it in. I am currently breastfeeding, and I love that the IUD will not make my period come back faster than it normally would. They say that you can expect heavier periods with slightly more cramping ect for the first 6 mos or so after getting the copper IUD, sometimes with spotting in between, but I haven't had my period while on the IUD yet so who knows? I might just get lucky and have my period not return at all until that first 6 mos is already past - wouldn't that be great? Anyways, as you can tell, I really like it so far. I can't feel it at all, and my hubby has only felt the strings once, and I also just read that after about 3 mos the strings really soften up and get alot harder to feel anyways. I love the convenience of not having to remember anything or disrupt anything but still being "baby-proof"... and with an 18 mo old and a 3 mo old, I definitely want to have a little break before the next baby arrives!!!
PS: I have always been interested in trying the NuvaRing, but I hate that you have to wait 6 mos or more after giving birth to use it if you are breastfeeding. My period came back only 4 mos after having my first baby, and I got pregnant again at 6 1/2 mos after! I HATE the pill because I can never remember to take it and I hate how the hormones mess with my body, so I chose to try to IUD this time, and I figure if it doesn't work for whatever reason in a few months I can get it out and then go on the nuva ring anyways. But, so far so good!