There are a few different types of bottom surgery. so it depends on which you are talking about.
You should do some searching around on the internet to learn about each type of surgery and their pros and cons.
I'll briefly tell you about the two most common, and you can go google them to learn more.
Phalloplasty : This is where they take flesh from your arm or somewhere and create a penis out of it and attach it to you. You would not have much pleasure feeling because of what it came from. and it also couldn't get erect. but the benefit is that it can be a full sized penis.
Metoidioplasty : This is where they kind of re-position and sculpt around your clit(/penis) which has already been enlarged from testosterone. So the benefit of this is it can get erect and has much more pleasure feeling. downside is that it is very small.
hope that helped. now go use google