Is it recommended to flash benq 1620 to 1625?

So, you pros, is there any advantages in that modification?

If the answer is yes, how should I proceed?

“The guy who just bought two 1620’s yesterday”

No their isnt any advantage to flashing the 1625 firmware, the 1625 requires extra hardware to burn Lightscribe discs which the 1620 does not have, the 1625 also does not support overspeeding media like the 1620 either.