This is the moment that you will have to find what you really need and how you will use this drive, as i said before you should be able to reach 16x for reading*, but it would be very hard to reach 16x when you will burn.
But most of the users here only burn at high speed for testing, so if i assume that you will burn at 12x you wont have any problems.
*i’ll try to do some test with my external LG later tonight.