QSI Quanta, a manufacturer for optical drives. Actual Pioneer DVD-writers are QSI-design.
The last original QSI-drives I had were over 10 years ago, Slimtype DVD-ROM/CD-RW-drives
I guess it use MTK-chipsets like LG, Liteon and Samsung since years.
Pioneer BD-drives use Renesas-chipsets, the design is different to the QSI-based drives, the case is shorter than the BD-drives.
I´ve had also the “fastest” CD-RW-drive which had exist, a Mitsumi 54x. In the end it was slower than some of my 52x-drives from MSI (Optorite), LG and Liteon were faster and produce mostly better quality.
With a good disc and good writers you will get very good results with 32x and 40x speed and not loose much time if compared with 48x or higher