Hi!, I have this DVD burner Benq DW1640 i bought back in 2006. I burned hundreds of DVDs so far with no major problem, the only being a strange noise it does sometimes when closing the tray. I wonder if i should bought a new burner or keep using this, not only because of new technolgies (speed is not a problem since I always burn at 8x although i could burn till 16x) but quality of burned DVD concerns me, If I should change it I would receive suggestions about good new models being sold at present, Thanks!
Simple advice.
If you are satisfied with max 16x burns keep the DW1640 untill it dies. It’s the best 16x burner ever built. 
Nowdays Pioneer makes the best burners. 
BTW, slow tray movement and/or additional souds are quite common also on my 1640’s from time to time although one of these drive made 500+ DVD burns in 2 years time.
Pioneers? The Best? Thank goodness I have 2.