Time in WinRAR most definitely relies on compression. No compression = direct copy on extraction (e.g. very little cpu activity).
While I haven't seen this in writing for QuickPar, QuickPar does display what program generated the pars (upper left if I'm not mistaken) and it seems that pars generated with quick par generally scan fast while those not made by quickpar can be dog slow. It's not always that way, and file size (especially dvd rar chunks around 50mb) can impact scan time. Also, as far as rebuild time, I have no rhyme or reason why sometimes several megs are missing it it fixes it up uber quick while sometimes an idiot puts an nfo file in that's 2kb and it takes like 8minutes to regenerate. It must be something to do with how par data is stored and/or variations in storage between programs.
_ _ - - = = Pr3tty F1y = = - - _ _