I got the game 2 weeks ago, played over 60 hours, and never had a single crash/CTD/freeze etc. The game is rock stable for me.
My only problem is my mouse cursor giving me fits when I have to choose between 2 champions and can't see any descriptions when overing over the tiny icons. It's not working for me.
Also, a little annoyance. I'm using 3X 30'' LCD side-by-side (active desktop in Win 8) with 3X Nvidia Titans, and I'm playing the game on a single screen (the center one at 2560X1600), but when trying to mouve the screen with my mouse on the tactical screen, it gets out of the game and on my desktop lol instead of moving the screen!, so it takes me 2 minutes to move the screen around on the battlfield.