My wife and I switched from AA to NW this year. In our combined flying (50+ segments this year) we've had one unfortunate issue (with a dork here at FLL), but otherwise outstanding service. And even with our "incident" a call to the Gold Elite desk dealt with the issue -- they even went so far to call the gate at my wife's connecting point (MSP) to speak with the gate agent and make sure she was upgraded on that leg...

We're very, very happy we've switched!

Steve