I dont personally have this but my sister has a copper IUD and loves it. Personally I was VERY happy to be off any sort of hormonal birth control - so happy that I decided I'd never go on it again. My son is 10 months old now and we figure we'll think about trying for #2 once he's 13-18 months old.
After 6 months, which is when I introduced solids to my son, I started charting my fertility as a method of birth control. (Incidentally, fertility charting has a 0.4% unplanned pregnancy rate - comparable to the pill - recently published in JAMA). I've personally been VERY happy with this method and also like the Taking Charge of Your Fertility book. (I also have not yet ovulated - it's been 10 months and I'm expecting it any day now, but then, I've been expecting it any day for the last 2 months).
Yes, there are some women who get pregnant while breastfeeding, but IF you're exclusively breastfeeding and IF your baby eats no solids and IF you're less than 6 months out it's 98% effective as birth control.
For my sister, she had her IUD inserted at her 6 week pp checkup and for her it was not going to be cost effective (due to copay and insurance) if she kept it for less than a year. She's been very happy with it.