say T6.
for me a 3 year old drive is old for 3 reasons
1. LED inside the optical drive are becoming less and less durable
2. optical devices are becoming less and less reliable on many brands, won't say more names, already did it here
3. the usage of each drive can vary, i have seen people not using drives and the drive dying just like that, a friend have a pc that after 3 years, the drive just died, if it is not a plextor is a sony and he doesn't burn much cds, another friend after 6 years of no usage of the drive(the drive is clean, i cleaned it)refused to read a simple dvd-r, my external dvd drive could read it perfectly
i have seen people burning as much as 30 dvds per day in a drive, this killed the drive in 6 months, the drive said that the warranty for home use was 3 years and for commercial use was 1 but 6 moths with that usage left it blind to record and only could read cds, not dvds
i work with this drives every day, not just my small perception of 3 or 4 drives i purchased and i use in home to listen to cds, i am a pc technician, i purchased this external dvd drive just for this exact reason, i never can trust on the drive of the pc i am going to fix, it is usually dead or failing and i am not going to talk about the problems of drives refusing to open, god knows why this happens
so forgive me if i call a sony drive with 3 years of use a old drive