Suzanne
While the Pioneer 104-105's were used in the shipping MAC's, now Apple uses the Sony (?) drive that does DVD- and DVD+ but only enabled for DVD- in the new Mac's and iMac's. The major difference I can find is that the Sony -+ burner does CD burns at 24x where the Pioneer A06/106 is limited to 16x CD burns.
I recently purchased an EZQuest packaged Pioneer A05 with a FireWire interface and have had no problems with it. EZQuest can be purchased at several places with www.macsales.com being on of the best for support.