How rugged are they? I like to run off several CDRs at a time for work (30-50 in an eve every so often). I ask as I will be looking at a new unit with a combo drive and It will be slot loading. Can it handle the continuous abuse on top of regular usage? This will instrumental in whether or not I keep this ext Lacie (x12 - what is that worth anyhow??) I have. Anyhow, would love to hear something... Thanks a mil.