Philips doesn’t have a “own” production line and BenQ is out of manufacturing bussines, so it’s safe to say; they are both from Lite-On.
Both drives also seems to be based on MediaTek chipset, (not quite sure about this though).
What differs. SPD2412 is a 18x burner (as stated on Philips site). SPD6001 also supports LightScribe.
SPD6001 might be a Liteon SHM-165H6S, but I am not sure.
Man I was wrong… :o
Now that Jan70 posted new firmware for SPD2412 it shows up to be a Samsung drive (with MediaTek chip).
Don’t want to guess anymore but the SPD2412 firmware looks much like Samsung SH-S182*
Edit. ala42 also seems to agree this is a TSST drive, linky
Link pic Samsung flasher.
pic1. SPD2412 fw extracted
pic2. Philips…? flasher