My boyfriend never complains that he can feel the actual device. He's only made a remark once about how he could feel the string (it feels like the stuff you would use for fishing) and that was after the first time we had sex without a condom. Since then he hasn't said anything.
I will say a few things as a precaution though.
-Before I had the Paragard put in I NEVER had cramps and now I have UNBEARABLE cramps (I seriously survive on a 3 at a time Pamprin regimen!)
-I used to be able wear a regular tampon for 6-8 hours, now my flow is EXTREMELY heavy and I bleed through a Super+ tampon in less than two hours for the 2nd and 3rd day of my period.
-I used to have 5-7 day periods, now they are 7-10 days (including spotting for both).
-I have pain during sex and the pain only gets worse AFTER sex. It extends from my lower abdomen down through my tailbone and it HURTS, A LOT.
*On the plus side, I've had it for over two years now and it's worked effectively to prevent pregnancy. I think I would almost rather deal with the pain than:
1) Pregnancy and Labor
2) Birth Control with hormones
3) Daily pill popping
4) Hormonal side effects from normal birth control (ie. Weight gain, acne, mood swings, etf etc)*
I should also mention that I have NEVER had a child and chose this method of birth control because of my horrible experience with Depo Provera, which caused lumps in my breasts (that were benign, it was hardened tissue). That instantly made me think "Hormones = lumps" and therefore wanted the Paragard because it did not have hormones