I tore my ACL completely last year. Also meniscus damage. My doctor (head of Ortho at a top medical school) is very anti-brace. He wanted me to get the leg as strong and flexible as possible before surgery. His theory is, the stronger the knee, the better the recovery.
Before surgery I did 2-3 months of physical therapy, and as much bike riding as I could handle. The injury prevented me from standing on the pedals, so I sat down when riding. I did up to 30 mile rides. No brace, but I was gentle on the knee, no running or any impact. No twisting. Stairs were a pain to navigate. Didn't even clip in to the pedals for the first month or so.
Once the inflammation was down and the knee stabilized, we did surgery. Cadaver graft. I had a full-leg brace for the first week, after that, the doc took it away. Day 10, I was back on the bike and I also did physical therapy 2-x/week for 3 months. I rode an 800 mile bike tour 4 months after surgery. It has now been 9 months and the doctor says I'm good to do anything - no brace. Thinking about skiing (gently) in a month or so to see how the knee holds. Still a little tepid about it, we'll see.
So, that's my experience. I'm very happy I did the surgery and I think the key (for me, at least) was the physical therapy before and after.