To become success story

If I want to revise the paper (e.g., submit a revision of a rejected paper to a different conference), the original appearance is not desired, and usually I need to produce a different format, so it does not matter much if the original class and template no longer works. What matters is that I can easily copy my text to the new template. That is mostly easy, but recently I have had to deal with templates that want all kinds of meta-data, and place standard elements such as \title and \author in a non-standard location, which makes things somewhat time-consuming. But the main part of the paper can be reused and revised, with a formatting pass at the end.

Concerning longevity, I have rarely had the need to process a really old work, but just to see how well it works, I have tried a thesis from 1990, and the main text works (graphics are separate, and I would have to invest more time to find out how they were built). I also tried papers from 1992 and 1993, and they compiled fine; the paper from 1992 contains Framemaker graphics, and I no longer have a way to convert that to Postscript, but fortunately I have the Postscript output; for one picture, the placement is slightly wrong, though. The 1993 paper looks fine.

Maybe the advantage with these old papers is that there were no style/class files coming from the publication venue, so I just used article (or, for the thesis, report), and not many packages, either.