Ah, you still meant you need a viewer INSIDE RC? Thats different. I thought you wanted to use something external. Well, if there is no such viewer in RC (which I doubt), then there is no way around an export, right?
Just out of curiosity, what’s so difficult about exporting it? Is it just this one step more that we all wish we would’nt have to make ourselves? 
Been there many times… lol
About “better”: its all very subjective. What is better for you might be worse for somebody else. Hence my question. So you mean by better a higher texture utilization? I think it means how much of the file is used by the unwrap, right? In my case, that couldn’t matter less, which is why I never change much there. But I understand that for other purposes, like loading it into a game engine, it can be quite important.
How much the texture utilization changes might also be highly dependent on the object and how the images were taken, I imagine. Your example is very straightforward, basically aerial photography with all cameras at almost the same distance to the object. But if the object is more complex and the surfaces are at very different depths in one image, the results might vary much more since there will be areas with much higher possible resolution than others. And if you then use adaptive texel size I recon that the texture utilization will be higher since some areas will have to be bigger due to a higher resolution.
Texture quality is a whole different story. I never quite understood the principles behind that. I think it puts the resolution of the image in relation to the achieved texture resolution. But I suspect that it is somewhat arbitrary for the same reasons as I mentioned in the last paragraph. I had a very simple object similar to yours (a wall) where I got 100% texture quality without doing anything special. Then I had a very complex roof space where I paid much more attention to alignment quality and even used RAWs instead of in camera JPGs (in the former project) but only got an abysmally bad texture quality of 35%! The resulting texture however is as good or even “better” than in the project with 100% texture quality. So I guess that the value can only be a guideline.