If you do no editing, such as adjusting light curves, color balance, white point, sharpening, etc. prior to converting to TIFF or JPEG, then the only difference between the finished files will be whether you allowed the automated routines in the camera make the decisions (JPEG) or the preset/automated routines in your conversion software application make the decisions (RAW->TIFF). Whether the original RAW file is compressed or not will make no practical difference. Only when you are doing very precise editing to bring out very minor differences in the extreme highlights exposed very near to the saturation point will the difference between compressed and uncompressed NEF files be noticeable.
It's not so much that a RAW file (lossy compressed or otherwise) has that much better image quality than a TIFF or JPEG, it is that the RAW file contains more information than either of the others, and that additional information can be used to bring the image closer in terms of white balance, color, and dynamic range to the photographers intent. But to leverage that additional information into the final appearance of the image requires editing the image and adjusting light curves, white balance, etc.
The advantage of RAW over lossy formats isn't that what you see when you preview a RAW image on your monitor will look better than a JPEG or TIFF. This is because all of the data from the RAW image is not displayed. Your monitor is not capable of displaying anywhere near all of that data at once. What you see is an on-the-fly conversion to a format your monitor is capable of displaying, much like a JPEG would be.
The advantage of the RAW file is that all of the information captured when you created the image is still contained in the file, even if all of it is not currently being displayed. When you edit a RAW file, what you are doing is selecting and choosing exactly which parts of the data are displayed and which parts are not used. You are choosing the points at which subtle differences in brightness, color, etc. are emphasized and at which points fairly significant ranges of brightness, color, etc. are rendered the same.
Once that information is converted to another format, such as TIFF or JPEG, the unused information is discarded and can not be recovered from the converted file, because the converted file does not contain the unused information.