Just because someone pays the tests, that doesn't mean the tests are biased. Such tests are quite common in security segment, particularly antiviruses. There is however a catch that party paying for the test can decide not to publish the results if they are unfavorable to them. Which can still provide an internal audit for their services/products so they improve upon them and try again. If they are favorable, they usually go ahead and publish them. It's of testing body's best interest to be impartial if they want to be taken seriously for the future as testing organization. Paying them to do the testing is simply that, paying for the service of doing the tests, not paying to be shown as favorable.
As for everyone having doubts, just look at the evolution of AMD's control panel. Back in Radeon 8500 days it looked horrible. Then CCC came and while it was heavy, it was a massive leap forward. The modern interface they have now makes NVIDIA with it's "2004" interface look like a sad joke. And not only that, the control panel is super responsive, applying settings is instant and it's just nice to use and comes with OC tools out of the box.
What does NVIDIA have? Prehistoric looking interface that's all cluttered, bugged and horrendous to use, it's flashing and resetting as you apply settings, just pathetic and sad. It's just an absolute mess that I wasn't a big fan of back in GeForce 6000 series times and same applies since I got back with NVIDIA with GTX 980.
As for driver itself, I've had many problems on GTX 980 and GTX 1080Ti which required months to get fixed. But they fixed them eventually (finally). About the same as experience with AMD up till HD7900 that I had last. So, on that front, they are about the same in my book. But that control panel difference...