<< rich - i have the same machine and had the same dilemma - the folks at OWc said the main difference between the units was that the 111 would burn dual layer DVD's - if I had no real need for that, they felt the 110 was actually a superior unit though a model older. I went with their recommendation, installed the 110 and it has worked flawlessly since putting it in. hope that helps. jay >> That was interesting since the following is the e-mail response from OWC on June 8th. I had the same question. <<Hi, This is Zach from the OWC Tech Support Dept. The difference in the two drives is that the 111d has a different firmware and at least 1 more option for burning the discs. I usually suggest the dvr 111d . ------------------------------------------ Sincerely, Zach Hyatt Computer Technician Other World Computing, Inc. 1004 Courtaulds Drive Woodstock, IL 60098 (815)338-8685 tech at macsales.com>> I believe from other research I did, that the 111D will burn to DVD-RAM and the 110D will not, but I could be wrong. I ended up buying 2 from NewEgg. com for $29 each plus change and shipping. They are now installed in both my QS and MDD, and they were both recognized in OS9 and OSX. I'm pretty sure I'll have to run Patchburn on both to use all the features without using Toast, but once again I could be wrong. STeve