What do you get out of the n`th hour researching a stock? I look up the history of the numbers in morningstar or gurufocus, think about the business (moat, etc.) for some minutes, fly over the annual report reading whats interesting to me and then add the numbers to my spreadsheet. After that i maybe read some SA articles or look if i find a writeup in VIC. Most of the time i know enough to pull the trigger after that. But with 4% positions i have room for mistakes and i mainly clone others, so my picks are already filtered.
I doubt that more information is helpful to make better returns, probably the opposite is the case. Its impossible to know what happens exactly in the future, so more information probably leads only to overconfidence.
I think it's useful to know the industry dynamics, the management's approach, who the competitors are, any potential regulatory problems on the horizon, looking at the filings and transcripts, etc. But to each their own.