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. I love the game! I totally hate Civilization, but LH, I can't stop plying it! 
My only problem is my mouse cursor that is 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. The cursor is buggy, and the icons are tiny at 2650X1600.
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, fullscreen, not windowed), 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, 1 mm at a time, to see those #$%! archers sneaking out of the screen lol!
In all my other games I have, the mouse cursor ''stays'' in the game, and never ''gets out'' of the game like that.
Any ideas?