Ive played 7 games thus far, but from those 7 games I can already say it is much better than Rift. Not once in a game have I ever felt completely hopeless, and in complete doom (except maybe once I hear those final dings of our nexus HP)
I have yet to play a game in which the score difference has been above 75, maybe 50, and I have even played a game where we lost 0-1. This type of game where you almost always have a chance at coming back and winning, or you always have a chance at losing no matter how far you are ahead is such a welcome change from the "10 minutes and the game is already lost" format of Summoners Rift.
Despite a few balancing issues which I highly doubt will ever get fixed (just look at the imbalance of 3v3) unless Dominion becomes the main game mode of League, I have quite a lot of fun in it so far, and look forward to a full release where game balances have been made.