I had a few complaints about the farmers in Carcassonne. I changed the scoring slightly to make them less powerful and that worked very well, and the River tiles make it even a bit better, in my opinion. In the original, the early farms in the middle often yielded huge points at gameend. The River helps breaks up the middle of the board which helps contain farms a bit more.

I also play that the mountain at the end of the river goes all the way to the edge of the tile in the one corner where it is illustrated to be close to the corner. I make that another 'fence' for the farmer, not counting the small strip of grass that connects the 'north' side to the 'east' side. That means if the farmer really wanted to get a farm that reached around the mountain to the other side, he has to spend an extra diagonal tile to connect the fields.

Excellent addition. The River is so good that I enjoy Carcassone even without the Expansion as long as I have the River.

I've played Carcassonne many times with and without both expansions. The trick to winning is to compete successfully for farms while keeping in the running with other points-making. Apparently, the river tiles were introduced to keep the game from becoming simply a competition to win the one monolithic farm. In most games I play without the river one significant farm determines the winner, and with most games with the river tiles, this is not the case. Once in a while one huge farm will still spring from a game with the river tiles, but this is usually due to some crafty playing by the winning player, who is then justly rewarded. The river tiles elegantly accomplish their intended use without corrupting the simple yet subtle nature of Carcassonne.