@zakcat i'm not sure who you are replying to, but if you have selected the doctor well then you have no reason to be concerned. Your first TKR finally got better, although it took longer than you anticipated, correct? Since your first knee was good then I am sure your second one will be too.
Although I opted for the Conformis knee because I read that it has an easier recovery since it is made to be the same as your natural knee was, I have pretty much heard that the biggest difference in recovery is in the skill of the surgeon. I think of my recovery as being great and the knee never hurts except occasionally a little twinge when I have overdone exercise.
I hope your second TKR goes well, let us know how you are doing when you are feeling up to corresponding.
JK

@zakcat - Don't be scared. I had my 2nd TKR in January of this year and it was a huge success. It's better than my first that was done in 2017. I'm pulling for you. Will you keep us posted? What are you most scared about?