I voted for the LiteOn SHM-165P6S this time.
It's less quirky than my two Pioneer 111 series drives, which are so different from each other that I have to make different MID substitutions in firmware for the two drives in order to get optimal results, and one of them makes a huge jitter jump if I burn faster than 24x for CD-R or faster than 8x P-CAV/12x Z-CLV for DVDs.
So I'm not as impressed with the Pioneer 111 series. Two quirky drives can be bad luck, but I don't feel like being unlucky a third time.
The LiteOn is a solid performer, and it's a fairly good DVD scanner.
It's also one of very few drives I have that can rip CDS 200 protected Audio CDs properly in secure mode (the other being a NEC ND-3500AG and a Matshita UJ-840S laptop drive).
I would vote for the BenQ DW1655 if it was still on the poll however.
Pioneer DVR-112L, LiteOn SHM-165P6S, Pioneer DVR-111L, BenQ DW1655, Plextor PX-760A
LiteOn LH-20A1P, Optiarc AD-7203A, Matshita UJ-840S, Sony RDR-HX910, Sony RDR-HX750