I've had a port since I was 11 (and I'm 18 in a few months). I got sick of having IVs in my arms. They wrecked up the veins so much they started to use my wrists to give my arms a 'break'. So I asked for a port and I've never looked back. Yes I'm on port number 3 now, but its different with everyone, as ports usually last a long time. Number 1 for me lasted a few months and got a clot, so it was replaced. That one lasted 5-6 years. Now number 3 is still going strong after 1 1/2 years <img src="i/expressions/face-icon-small-happy.gif" border="0">
Mine is in my chest, aparently arm ports are easier to hide but the chest ports are more easy to access. I do have 4 scars from having ports, one on either side basically where my bra strap sits and two tiny scars that are basically invisible on either side of the base of my neck. (After port number one kicked the bucket, they swapped from my left to my right side)
Yeah there is a small bump where the port sits but i think it is basically to do with what size port they use as my old one was smaller. I do have a tube from the current port that sits in my neck, and yeah you can see it, but I couldn't care less and even though its noticeable, people don't ask questions or stare, and most don't even know I have CF. Maybe they're just too kind!
It takes just two seconds to put the needle into the port for IVs when putting the IV in my arm would take what felt forever. It doesn't hurt, its just a pinch as its the surface of your skin. I refuse to let anyone take blood from mine though, as I think that may have been teh reason why number one broke, plus I don't get much blood back from it in the first place.
Hope that was helpful, I sure didn't seem able to shut up for a while!