I make "proper proofs" of everything. Not only do they help me keep my process in check and help identify problems easily (exposure mistakes, light leaks, compromised batch of developer, shutter problems, meter problems, etc.) but, when filed together with the negatives, they make finding any particular image much quicker.
I find the "proper proof" to be the most helpful since I can use it to make small changes in my processing as needed, e.g., a change in negative development time if contrast at one time is consistently off, or a change in E.I. if I find that shadow detail is not consistently rendered optimally. Highlight and shadow proofs don't give me the information I need to make such changes.
I don't need a proof to tell me what the final image will look like; my proofs never look like my finished prints...
And, I can sit down with my proof sheets (four 4x5 images per sheet) and a set of cropping Ls in normal room light at table and decide which images I may want to enlarge. No light table needed.
Still, I agree with ic-racer that evaluating the negative under magnification is really helpful. I do that as well. One doesn't exclude the other.
Best,
Doremus