My PRS-650 is now 6 months old, not an issue
PRS-T1 just arrived at home so it is the baby of the ereader family in our house.
PRS-300 is 18 months old and a good as it was the day I got it. Being my first ereader, it has much sentimental value.
Kobo is over twelve months old and has never, ever caused me any issues
My bride's JBL's are a year old now and working as advertised but at the moment she is thoroughly enjoying her brand new Kindle 3.
There you go