I used Avent Duo for around 15mths.
Then passed it to my friend who used it for 4 mths.
Then passed it to my husband's friend who used it for around a year.
Then passed it to my colleague who used it for 6 months.
Total usage = around 3 years ++
Total age, around 4 years (cos I bought it 2nd hand)
By usage, I mean pump on daily basis, at least 3-5 times a day.
In btw, it just sat in my storeroom
It's still in excellent condition & it's a worthy investment (so many ppl benefitted from it)