Also your climate as the Fass has two more filters to gel in the winter time. Almost always they are mounted on the frame rail where they will not be protected like the stock on is making them more likely to gel.
I've ran the Fass for three years now with no problem. Its really quiet compared to the older units. They were loud!!! I had the PPE when I first started out and I went through three of them in a year before I decided to buy a Fass.