I know it is a pretty low priority to most people, but, it is illegal to rip CDs and then sell or give away the same CDs --that violates "fair use." If you sell or give away the collection a second (and later, third, fourth, etc.) purchaser will be acquiring the music without the original license holder getting any royalties.
I am in the process of ripping my collection (currently up to 2100 CDs ripped. I will be keeping the original CDs. Given how much work is involved (A LOT--to correct/complete metadata for classical cds), I expect to never have to re-rip the CDs (the NAS is backed up). Aside from security issue, I am not convinced that current ripping is "bit perfect" so that once ripped, one has all that can ever be extracted from the CD (as the original source). Not that I trust "Absolute Sound" (certainly not absolutely), but they did publish a "study" that showed differences in the way the files were ripped and stored (FLAC vs. WAV) and between the software used to do the ripping. I have heard a FLAC vs. WAV demonstration where differences could easily be heard (in favor of WAV), and quite a few users have reported that CD playback through a particular DAC sounded better than playing back a ripped file of that CD through the same DAC. This suggests another reason to hold on to CDs for at least a little while longer until one can be absolutely assured of perfect retrieval of what is on the CD.
I am in the process of ripping my collection (currently up to 2100 CDs ripped. I will be keeping the original CDs. Given how much work is involved (A LOT--to correct/complete metadata for classical cds), I expect to never have to re-rip the CDs (the NAS is backed up). Aside from security issue, I am not convinced that current ripping is "bit perfect" so that once ripped, one has all that can ever be extracted from the CD (as the original source). Not that I trust "Absolute Sound" (certainly not absolutely), but they did publish a "study" that showed differences in the way the files were ripped and stored (FLAC vs. WAV) and between the software used to do the ripping. I have heard a FLAC vs. WAV demonstration where differences could easily be heard (in favor of WAV), and quite a few users have reported that CD playback through a particular DAC sounded better than playing back a ripped file of that CD through the same DAC. This suggests another reason to hold on to CDs for at least a little while longer until one can be absolutely assured of perfect retrieval of what is on the CD.