When you're in the Develop module, and adjusting with Details controls (Sharpening, Noise reduction) you need to view the image at 100% in order to accurately see the effects of the details settings. Judging noise reduction and sharpness with any view other than 100% will not give you an accurate picture.
Open the Details panel, and zoom to fit. You'll notice a warning icon in the Details panel. Zoom in to 100% and the warning icon goes away.
You're right. When I magnified the view to 100%, the results in the two modules were identical, as you said.
It does, however, raise a practical difficulty for me. With these kinds of long exposure, high ISO pictures, if I zoom in to 1:1, I find it extremely difficult to make any adjustments because the noise is so high. I would basically set all the noise sliders to max, and the details to minimum. However, this results in overadjusting for noise and losing too much detail when the picture is viewed zoomed out to fit on a computer monitor as a slideshow. Usually, this is not a problem, but at the high ISO/long exposures of these pictures, I find it very difficult to work in the develop module at 1:1.
Yes, it is a tradeoff. I'd recommend using the 1:1 view only for adjusting sharpness and noise reduction, and reverting to the "fit" view for all your other adjustments. You'll just have to "know" that the noise reduction has been correctly set, even though the results may not be visible when you fir to screen. The fit view is good for most other global adjustments, though.
Of course, what we all want is to have those 5k monitors on our desktop...