The DVD-E818A6T appears to only have a 198KB buffer. I've been trying to find the DVD-E818A4T which, according to ASUS' website, has a 2MB buffer. No luck so far. Maybe it's just vaporware!
I've been running an ASUS 16x PATA DVD-ROM and an ASUS 52x PATA CD-RW for years now along with my Pioneer and Optiarc SATA DVD-RW's and they've been great - smooth, quiet and will read or write anything. But now my new ASUS i7 930 mobo doesn't have any PATA IDE connectors at all, just SATA connectors (fortunately there's 8 of them).
There seems to be very few SATA DVD-ROM drives on the market right now. I'm going to try a couple of Vantec PATA to SATA drive converters (as soon as they arrive) to see if I can just continue to use these PATA drives in an all SATA system.