I dont post often, but I think I should share my experience here.
A few months ago I had a testicle removed due to testicular cancer. (I went through treatment and am now 100% cancer free.) Beforehand, they gave me the option to have a prosthetic put in, but it would have to be a couple of weeks after the initial surgery. I decided to wait it out and see what I thought. It wasn't as noticeable as I suspected, though I could see a huge difference. The incision from my surgery was a couple of inches below my waist, while the prosthetic would be inserted through the scrotum. I decided one scar was enough The last thing I wanted was more surgery in that area, so I opted not to get the prosthetic. I still have the option to have a prosthetic put in, but I dont think its worth it in my situation.
Over time the remainig testicle seems to be making up for its lost companion to some extent. My semen amount seems surprisingly close to what it used to be (i was a heavy shooter), and I believe the testicle has gotten slightly larger, though that may be my imagination. Moreover, none of the ladies I have been with have seemed to notice I was missing something unless I told them. The seemed much more interested in my cock than examining my nuts (or lack thereof :biggrin1

. My scar is in the same location as a hernia surgery scar, so it really doesnt point to having my testicle removed.
I think its a mental thing for the most part. If you worry about it too much then you will have a negative exerience. If not, then you wont have any trouble. I've carried on like normal, and had no problems.
If I ever get around to it I will post some current pics in the gallery - sorta like a before and after thing. But I dont make a habbit of taking pics of my manhood, so it might be a while before I get to it.
Anyway, I hope that helps some.