Do you always keep the original file of your books?
I am doing some cleaning up of my library since I am about to get an epub (as opposed to mobi) reader and I am wondering about keeping original files. In the past, I always kept the epub when converting from mobi because it can be easily edited if there are mistakes. And I am keeping the mobi files because I can email them to the Kindle apps on my iDevices. But I have some old PDB files which were liberated and then imported into Calibre, and I am wondering if there is any benefit to keeping them, other than 'they are the original file.' I can edit the epubs with Sigil and epubs are a better format, no? So is there any benefit to keeping the PDB or should I just trash them?