In the Library module the preview is based on the jpg preview setting in Preferences | File Handling. In the Develop module the preview is rendered in real time from the original raw file. The way the image is rendered on the screen will therefore differ in the two modules, especially in views other than 1:1. In views smaller than 1:1 the inaccuracy of the Library module views are often obvious and decisions on sharpening and noise reduction are better done in the Develop module.
An excellent way to make decisions is to set your viewing in the Navigator to 1:1, and use the spacebar to toggle between that and the Fit option that shows the entire image. When viewing images one at a time in the Loupe View hit the Tab key to remove the left and right side panels or the <Shift> and Tab keys for an even larger unobstructed view of the image. Now you can cycle through images with the arrow keys and instantly pull up the full sized view of the image for a check on the quality of the processing that has been done.
In the 1:1 view you have the ability with the mouse to move the image around in the window to inspect the various portions of a large image.