Yes, the size is the difference between DVD and CD. I don't use them as my only backup source, but they are a pretty quick way to do it, and I have old CDs that I've never had any problem accessing data from so I like them alright. (Until my 2 year old finds them...then all bets are off.)
"You can do anything, but not everything" ~David Allen~
LOL Rachel. I've heard that CD's and DVD's life span is about 5 to 10 years, but as with anything, you can be very lucky, or not at all. I've never had any trouble with those so far, but they are getting old, so is my EHD, which pushed me to buy a new one and have at least 2 EHDs.
But, hey, you know what they say about hard drives (internal or external)? The question is not IF they will crash, but WHEN!