I have also read, but may not be remembering correctly, that the NEC chips are better burners on a case by case basis. Maybe someone else can comment on the truth of this.
NEC chipset drives can be the best burners on the planet, if they're designed right and have good firmware.
The old Pioneer 111/211 through 117/217 series and the Sony/Optiarc 7200/7201/7203 series drives were great. Not only that, but both the PATA and SATA versions of the drives worked equally well. They are what gave NEC it's modern reputation.
Unfortunately, in the switch to the Sony/Optiarc 7240 and 7260 series of SATA-only drives, something was lost. They don't burn as well (except for DL media), don't feel as mechanically well put together, and frankly, we're all just sick of seeing them because they are now the only game in town. All of the rebadged Lite-On drives that use NEC chipsets are using some variation of the 7240/7260 design. There is no technological diversity, which is bad. You're stuck with a bunch of drives with different model numbers and names, which are all essentially the same. Just about everyone here already owns an original Optiarc AD-7240S or AD-7260S. We want a NEW drive, not the same freaking drive with a new name slapped on it. Where is the variety? Where is the innovation? Where is the excitement? THAT is what people are disappointed and upset about. They LOVE the NEC chipset, they just don't love what's happened to it in the last year or two.
I'm glad I stocked up on the older NEC drives when they were available new. The newer ones are just not as good.
Also, in regards to NEC vs. MediaTek, over time, there has been an exponential improvement in the burning quality of drives based on MediaTek chipsets. In the old days, people used to laugh at Lite-Ons and other MediaTek-based drives as being crappy burners, and only useful for scanning. Those days are long gone. It all started with the Samsung SH-S182D and SH-S203B, along with the Lite-On LH-20A1P and DH-20A4P, each of which set new standards for burning consistency and quality that hadn't been seen before in MediaTek drives. Now, drives like the MediaTek-chipset Samsung SH-S243N are considered to be the best burners on the market, period. So, while people still value MediaTek drives for their scanning abilities, they're no longer slouches in the burning department either.