Ok, but how much is slightly lower accuracy? Having real data vs guesstimated would be a big deal on fine changing detail. It would be irrelevant on something like a car shot that is all basically the same color.
It depends on the level of detail in the original signal, and the amount of (photon shot) noise. Light doesn't have an absolute brightness, only an average, there is always noise involved. Detail doesn't have an absolute level, there is also a lens/diffraction/(de)focus involved and subject motion and camera shake, and usually an OLPF to reduce the tendency for aliasing inherent in discrete sampling. So when it's not easy to say what the signal was, it's also not so easy to say how much exactly the signal was off.
So the 'slightly lower' can only be answered in a statistical sense, or compared to an ideal laboratory setup, and the answer will not be a simple number but rather something like an MTF curve which needs interpretation.
In the current season a landscape of mountainside with snow covered trees would be a big difference in the detail of the shot. Bayer shots like this have always looked artificial to me. Typically you have to downsample much more on natural textures.
Looks are hard to comment on, but from my experience it often has to do with inadequate Capture sharpening (assuming good technique was used to get the shot). Digital cameras just record what's thrown at them, and the sensor technology just makes a difference in which artifacts are tolerated or suppressed, but they all produce artifacts, no exception.
Bayer CFA sensors have a slightly lower Chrominance than Luminance resolution, but Chrominance usually has a lower level of signal detail anyway compared to Luminance (just look at the color channels of an image in e.g. in Lab mode). Also, the different sampling density between Red/Blue and Green can cause False color artifacts.
Sensors without an OLPF by definition exhibit more aliasing artifacts (although DOF/defocus can function as a Low-pass filter), and sensors that sample R/G/B for each pixel will only have Luminance aliasing. In the Foveon desgn especially, the channel separation is not that simple (the Raw sensor data is almost grayscale), and it requires significant processing which boosts noise and limits high ISO robustness, also because of the small well depth per channel.
TANSTAAFLCheers,
Bart