The Optiarc AD-724xS or AD-720xS series might be good for you to try.
BTW, it's not been fully proven or disproven that the DVR-218 is a bad model. No one has yet to extensively test this new design. It's not yet known how comparable it is to other drives that use MediaTek chipsets (like LiteOn and Samsung drives) or the NEC Pioneer drives before it. I do know, however, that community support behind it is minimal at best right now, and we don't know how it handles RPC1, bitsetting, etc...so I wouldn't suggest it just because of that.
If all else failed, a LiteOn might be decent. If you select one of the newer models (like the iHAS324), be aware that there are two models: one with a MediaTek chipset that appears to be fully a LiteOn design (iHAS324 A) and another with an NEC chipset that appears to be closely related to, if not the same as, the Optiarc AD-724xS series (iHAS324 Y). Some have noticed that the former will be advertised as having the Smart Erase feature, while the latter will not, which is how you can differentiate. At the moment, community support for the NEC-based model is lacking in comparison to the full LiteOn design.
And in hopes that maybe you can recover your Pioneer...have you tried cleaning it or housing it in a different computer/enclosure?