When I purchased my V10 Last year of may, I put nothing but Backup DVD-R movies for a whole week this way I have the opportunity to Test the Endurance of the laser everyone kept talking about how it burns up and if it Did I would exchange it for a another since the Warranty would be still Honored(Best Buy has 14 day Exchange Policy for Systems).
After a Week it survived so I got it Chipped with Maxtrix Infinity and Till This day Works Like a Champ..
Over the Years I had V4,V5,V7,V9 and then Finally V10(Permanent Keep)..
Also Keep in mind to use Good Brand Blanks for Backing up Discs,Burn with Reasonable Speed and ALWAYS keep the Disc Dust Free that's what I do..All my friends with them they just lay the games all over the place and it would have Finger prints and dust etc..I.E Killing the laser and stressing it from Dust and Finger Prints..You Reap what you sow!
It's like almost Anything,with Little bit of luck and if you take the time to take care of it, it would last almost eternity..