Quieter and Quality burn model?: GSA-E60L or GSA-E40L?

Would like your help again.
Looking for an external DVD drive for my laptop.

Initially, I was between Samsung and LG.
And after reading some reviews and threads, I think I am going for the LG burner.

Now, I want to know which one model is “quieter” and “achieves quality burn discs (DVDs).”

GSA-E40L
GSA-E60L

Could you please asvise me on this? Speed is not so much the factor to me.

Also, it appears that these models doesn’t have on/off switch.
Does this matter? I was hoping to turn the DVD drive on/off by the switch when not using.

Thank you in advance!!