Currently I have the Samsung SH-203B, an LG GSA-H22N, a Pioneer DVR-115D a Pioneer DVR-212D and I’ve used the Lite-On LH-20A1 but it’s in a box under one of my desks right now.
The Pioneer DVR-212D and the Lite-On LH-20A1 seem to me to have the best read speed, not quite as good but still acceptable are the Samsung and LG drives.
Please note that my experience with the Lite-On on burning was pretty negative. It burned and tested bad six out of six dual layer disks of a brand that has over an 88% success rate in my Pioneer DVR-212D and LG H22N. Also three out of five Sony DVD+R also bad, after that I gave up and took in out.
I’ve also had problems using that same dual layer media in the Samsung, (standard single layer media works fine) however I periodically check for firmware updates for my drives and I just found an SB03 update and after flashing that I burned a dual layer disk and it seems to have tested error free so I hope that fixes the problem but one disk is hardly a conclusive test.