I think I agree with the masses of this forum who say that if Rabbi SOl owns original cassettes he is legally within the law to make digital copies of them for his own use providing he maintains ownership of the originals. Rabbi Sol has an additional moral question as to whether this is right when he knows the original issuer is going to some financial and technical trouble to re-issue many of the same lables. I'd say that the moral decision is in the mind of Rabbi Sol. Why not buy CDs you most want to have and use particularly if you don't want to 'convert' the liner notes, and either donate the old cassettes to friends or those who still have tape players? If you want to experiment with conversion, have a blast. I have done both, and my conversions don't sound like crap. They sound like the original cassettes, which in my experience have lasted quite well. I've got 40 year old magnetic recordings in excellent shape (And some in less than magnificent shape - ever 'baked' a tape?)

It has often been a good opportunity to re-listen to an album while digitizing it at the same time.

Meanwhile, I've done some converting from LP's which to me sound better than CD re-issues.

As to reliability of media, CD's are very variable. Cheap ones have a thin metallic layer on one side which will be damaged by just about anything. Others are subject to oxidation and delamination. LPs and cassettes in my opinion are more reliable as to saving something, because when a CD goes bad, it's gone. JohnInKansas is right about hard drive backups. Hard Drives will hold onto a lot of data for a long time, but they need to be backed up, too.