I got the Paragaurd - primarily because I am still nursing my 10 month old and prefer not have any synthetic hormones delivered to my baby via breast milk.
But I agree with Laurel, I prefer to keep my cycle as natural as possible while still having reliable, worry-free birth control. Minimizing the amount of synthetic hormones and medications into my body.
The insertion was a bit uncomfortable. A pinch lasting maybe 30-60 seconds. Afterwards I had some cramping for a couple days along with some spotting. I suggest bringing a panty liner with you to the Gyn. I have heard that it may make your periods heavier for a few months, but as I am still nursing my period hasn't returned yet.
All in all I love my IUD. It allows me complete worry-free birth control. I don't have to worry about taking a pill everyday, or even changing a patch every week. I appreciate that it is hormone-free.