the thing is , there are so many vivaro/traffic/primastars on the road that you are bound to hear more problems with them same as you hear about so many transits rusting .
The traffic/vivaro is very nice to drive , good on fuel and you barely notice there is a ton of water etc in the back.
They also have a very comfortable driving position .
The most reliable vehicle i have ever owned is a t4 vw transporter , no common rail ,very few electronics , and very very simple to fix .
They don't drive like a car though , they wallow round corners and are quite slow even the 2.5tdi , not very refined either , just an amazing reliable workhorse .