I bet the new Optiarc is a Liteon ihas 124FU with a different FW. Maybe unique with features, but I doubt it have the same built-quality like the last real Optiarc/Sony.
I´m also not a fan of Slimtype-drives. The performance is mostly more worse than half-height drives, and I also mean the reliability and write-quality. Some slimtypes are not bad with some media, but the the range is small.
Here we talked about Pioneer:
We not sure who did what, but the Pioneer BD-writers are good; the DVD-writers are maybe a victim of the FW, the actual drives like to overspeed so many media which is not the best.
LGs latest BD-writer is also better than actual DVD-writers (GH24NSD1 looks and feels so much cheaper than 24B0 and 24C0), but overall I would recommend the Pioneer. The BDR-209 is good with most media I used, BD-R and DVD-/+R