read the thread he posted carefully the whole point of it was this
Test your media and drive at the different speeds verifying them and checking them for errors, whichever speed has the fewest errors is the best speed for your system with that media.
Your burning speed does not affect the wii laser in any way. If anything is going to "kill" the laser it would be adjusting it to work outside of specs in order to read discs it isnt meant to. The wii drive is a DVD drive. Nintendo left the dvd command in because they were originally going to have a dvd player, but went with the "wii format" to avoid paying royalties. When a disc is read its read speed is detirmined by the firmware, hardware capabilities and media integrity. A bad burn (lots of errors) will cause the wii laser to do more work re-reading sections of disk, which does lead to more wear and tear over time.