I tore my ACL at 21 in my first rugby game my sr year.
It took about 6 months and 5ish doctors to diagnose it. Which means I lived without an ACL for quite some time. I went skiing/snowboarding and tried other sports, but never felt right, which is why I went back to the doc.
I had the surgery, and can't imagine life without having done it.
12yrs later, my "repaired" leg is just as strong as my other leg, and I never think about my knee when doing anything. I have never been limited doing anything because of the knee, this includes tennis, bball, rugby, skiing, soccer, you name it.
I would say if you have any issues at all with the knee to go for surgery. It has advanced so much that it really isn't even a big deal anymore, and 6 months rehab is nothing, if you don't have to think about it going forward.